Fluvial systems

@misc{hilgard186918709,
    author = "Hilgard, E. W",
    title = "-1870, Report on the geologic age of the Mississippi River delta",
    year = "1869",
    howpublished = "Report of the United States Army Engineers; 1969-1870",
    note = "talkorigins\_source = {true}; raw\_reference = {Hilgard, E. W., 1869-1870, Report on the geologic age of the Mississippi River delta: Report of the United States Army Engineers; 1969-1870.}"
}

@article{crossref1876alluvial,
    title = "Alluvial Basin of the Mississippi River",
    year = "1876",
    journal = "Scientific American",
    url = "https://doi.org/10.1038/scientificamerican04011876-211asupp",
    doi = "10.1038/scientificamerican04011876-211asupp",
    number = "14supp",
    openalex = "W4230132362",
    pages = "211-211",
    volume = "1"
}

@misc{humphreys1876report10,
    author = "Humphreys, A. A. and Abbott, H. L",
    title = "Report on the physics and hydraulics of the Mississippi River",
    year = "1876",
    howpublished = "United States Army Corps of Engineers, Professional Paper, v. 13, p. 92-95",
    note = "talkorigins\_source = {true}; raw\_reference = {Humphreys, A. A., and Abbott, H. L., 1876, Report on the physics and hydraulics of the Mississippi River: United States Army Corps of Engineers, Professional Paper, v. 13, p. 92-95.}"
}

@misc{davis1902river2,
    author = "Davis, W. M",
    title = "River Terraces in New England, in Davis, W. M., ed., Geographical Essays",
    year = "1902",
    howpublished = "Boston, Ginn and Co., p. 514-586",
    note = "talkorigins\_source = {true}; raw\_reference = {Davis, W. M., 1902, River Terraces in New England, in Davis, W. M., ed., Geographical Essays: Boston, Ginn and Co., p. 514-586.}"
}

@article{moore1926origin,
    author = "Moore, Raymond C.",
    title = "Origin of Inclosed Meanders on Streams of the Colorado Plateau",
    year = "1926",
    journal = "The Journal of Geology",
    url = "https://doi.org/10.1086/623270",
    doi = "10.1086/623270",
    number = "1",
    openalex = "W2069285082",
    pages = "29-57",
    volume = "34"
}

@article{king1929corrosion11,
    author = "King, P. B",
    title = "Corrosion and corrasion on Barton Creek, Texas",
    year = "1929",
    journal = "Journal of Geology, v. 35, p. 631-638",
    note = "talkorigins\_source = {true}; raw\_reference = {King, P. B., 1929, Corrosion and corrasion on Barton Creek, Texas: Journal of Geology, v. 35, p. 631-638.}"
}

@techreport{trowbridge1930building21,
    author = "Trowbridge, A. C",
    title = "Building of the Mississippi delta",
    year = "1930",
    howpublished = "Bulletin of the American Association of Petroleum Geologists, v. 38, p. 167-192",
    note = "talkorigins\_source = {true}; raw\_reference = {Trowbridge, A. C., 1930, Building of the Mississippi delta: Bulletin of the American Association of Petroleum Geologists, v. 38, p. 167-192.}"
}

@article{mahard1942the14,
    author = "Mahard, R. H",
    title = "The origin and significance of intrenched [sic] meanders",
    year = "1942",
    journal = "Journal of Geomorphology, v. 5, p. 32-44",
    note = "talkorigins\_source = {true}; raw\_reference = {Mahard, R. H., 1942, The origin and significance of intrenched [sic] meanders: Journal of Geomorphology, v. 5, p. 32-44.}"
}

@misc{fisk1944geological6,
    author = "Fisk, H. N",
    title = "Geological Investigation of the Alluvial Valley of the Lower Mississippi Valley",
    year = "1944",
    howpublished = "Vicksburg, Mississippi, Mississippi River Commission, 78 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Fisk, H. N., 1944, Geological Investigation of the Alluvial Valley of the Lower Mississippi Valley: Vicksburg, Mississippi, Mississippi River Commission, 78 p.}"
}

@article{doi102307211375,
    author = "Flint, Richard Foster and Fisk, H. N.",
    title = "Geological Investigation of the Alluvial Valley of the Lower Mississippi River",
    year = "1947",
    journal = "Geographical Review",
    url = "https://doi.org/10.2307/211375",
    doi = "10.2307/211375",
    openalex = "W2327685420"
}

@article{doi101086625561,
    author = "Kidwell, Albert L.",
    title = "Fine-Grained Alluvial Deposits and Their Effects on Mississippi River Activity. Harold N. Fisk",
    year = "1948",
    journal = "The Journal of Geology",
    url = "https://doi.org/10.1086/625561",
    doi = "10.1086/625561",
    openalex = "W2511230724"
}

@misc{fisk1955late7,
    author = "Fisk, H. N. and McFarlan, E. and Jr",
    title = "Late Quaternary deltaic deposits of the Mississippi River",
    year = "1955",
    howpublished = "Geological Society of America, Special Paper, v. 62, p. 279-302",
    note = "talkorigins\_source = {true}; raw\_reference = {Fisk, H. N., and McFarlan, E., Jr., 1955, Late Quaternary deltaic deposits of the Mississippi River: Geological Society of America, Special Paper, v. 62, p. 279-302.}"
}

@article{dury1958tests3,
    author = "Dury, G. H",
    title = "Tests of a general theory of misfit streams",
    year = "1958",
    journal = "Institute of British Geographers, Transactions and Papers, p. 105-118; Publication Number 25",
    note = "talkorigins\_source = {true}; raw\_reference = {Dury, G. H., 1958, Tests of a general theory of misfit streams: Institute of British Geographers, Transactions and Papers, p. 105-118; Publication Number 25.}"
}

@article{dury1960misfit4,
    author = "Dury, G. H",
    title = "Misfit streams",
    year = "1960",
    journal = "problems in interpretation, discharge, and distribution: The Geographical Review, v. 50, p. 221-242",
    note = "talkorigins\_source = {true}; raw\_reference = {Dury, G. H., 1960, Misfit streams: problems in interpretation, discharge, and distribution: The Geographical Review, v. 50, p. 221-242.}"
}

@techreport{leopold1960river13,
    author = "Leopold, L. B. and Wolman, M. G",
    title = "River meanders",
    year = "1960",
    howpublished = "Geological Society of America Bulletin, v. 71, p. 769-794",
    note = "talkorigins\_source = {true}; raw\_reference = {Leopold, L. B., and Wolman, M. G., 1960, River meanders: Geological Society of America Bulletin, v. 71, p. 769-794.}"
}

ABSTRACT A major characteristic of modern Mississippi River sediments is the orderly repetition of depositional events. This cyclic repetition consists of alternations of detrital and nondetrital deposition. Each major deltaic lobe is composed of a detrital lens or complex of lenses bounded on all sides by essentially nondetrital sediments indigenous to the basin of deposition. Examples of major cycles are provided by the modern and pre-modern lobate deltas. A shift in the point source of sediment supply is responsible for the abandonment of an active delta and initiation of a second cycle related to the new point source. The abandoned delta, deprived of nourishment, undergoes coastal retreat and inundation due to continuing subsidence. During this process, reworked and in situ deposits accumulate over the detrital lens, forming the bounding component of the cycle. The pre-modern deltas, varying in time of abandonment, afford a natural laboratory for the study of these capping accumulations. Two such examples, the St. Bernard and Sale-Cypremort deltas, are presented. Subdeltas or crevasses are scaled down versions of the major deltaic cycle and can be used as a model. Because of their smaller size and shorter duration, the processes of deposition and facies relationships of the detrital component can be more easily studied than in the major deltaic lobes. Vertical and lateral distribution of environmentally controlled facies within a deltaic mass are the result of the cyclic nature of sedimentation and delta growth. Some possible facies relationships are explored in a hypothetical sequence of overlapping cycles and compared with an actual vertical section taken at Fort Jackson, Louisiana.

@article{openalexw2097985193,
    author = "Coleman, James M. and Gagliano, Sherwood M.",
    title = "Cyclic Sedimentation in the Mississippi River Deltaic Plain",
    year = "1964",
    abstract = "ABSTRACT A major characteristic of modern Mississippi River sediments is the orderly repetition of depositional events. This cyclic repetition consists of alternations of detrital and nondetrital deposition. Each major deltaic lobe is composed of a detrital lens or complex of lenses bounded on all sides by essentially nondetrital sediments indigenous to the basin of deposition. Examples of major cycles are provided by the modern and pre-modern lobate deltas. A shift in the point source of sediment supply is responsible for the abandonment of an active delta and initiation of a second cycle related to the new point source. The abandoned delta, deprived of nourishment, undergoes coastal retreat and inundation due to continuing subsidence. During this process, reworked and in situ deposits accumulate over the detrital lens, forming the bounding component of the cycle. The pre-modern deltas, varying in time of abandonment, afford a natural laboratory for the study of these capping accumulations. Two such examples, the St. Bernard and Sale-Cypremort deltas, are presented. Subdeltas or crevasses are scaled down versions of the major deltaic cycle and can be used as a model. Because of their smaller size and shorter duration, the processes of deposition and facies relationships of the detrital component can be more easily studied than in the major deltaic lobes. Vertical and lateral distribution of environmentally controlled facies within a deltaic mass are the result of the cyclic nature of sedimentation and delta growth. Some possible facies relationships are explored in a hypothetical sequence of overlapping cycles and compared with an actual vertical section taken at Fort Jackson, Louisiana.",
    url = "https://openalex.org/W2097985193",
    openalex = "W2097985193"
}

@article{carlston1965the1,
    author = "Carlston, C. W",
    title = "The relation of free meander geometry to stream discharge and its geomorphic implications",
    year = "1965",
    journal = "American Journal of Science, v. 263, p. 864-885",
    note = "talkorigins\_source = {true}; raw\_reference = {Carlston, C. W., 1965, The relation of free meander geometry to stream discharge and its geomorphic implications: American Journal of Science, v. 263, p. 864-885.}"
}

@misc{dury1965theoretical5,
    author = "Dury, G. H",
    title = "Theoretical implications of underfit streams",
    year = "1965",
    howpublished = "United States Geological Survey, Professional Paper, v. 542-C",
    note = "talkorigins\_source = {true}; raw\_reference = {Dury, G. H., 1965, Theoretical implications of underfit streams: United States Geological Survey, Professional Paper, v. 542-C.}"
}

@misc{kolb1966depositional12,
    author = "Kolb, C. R. and Van Lopik, J. R",
    title = "Depositional Environments of the Mississippi River Deltaic Plain--Southeastern Louisiana, in Shirley, M. L., and Ragsdale, J. A., eds., Deltas in Their Geologic Framework",
    year = "1966",
    howpublished = "Houston, Texas, Houston Geological Society, p. 18-61",
    note = "talkorigins\_source = {true}; raw\_reference = {Kolb, C. R., and Van Lopik, J. R., 1966, Depositional Environments of the Mississippi River Deltaic Plain--Southeastern Louisiana, in Shirley, M. L., and Ragsdale, J. A., eds., Deltas in Their Geologic Framework: Houston, Texas, Houston Geological Society, p. 18-61.}"
}

@techreport{mckee1967evolution15,
    author = "McKee, E. H. and Wilson, R. F. and Breed, W. J. and Breed, C. S",
    title = "Evolution of the Colorado River in Arizona, 44 of Bulletin of the Museum of Northern Arizona",
    year = "1967",
    howpublished = "Phoenix, Arizona, Museum of Northern Arizona, 67 p",
    note = "talkorigins\_source = {true}; raw\_reference = {McKee, E. H., Wilson, R. F., Breed, W. J., and Breed, C. S., 1967, Evolution of the Colorado River in Arizona, 44 of Bulletin of the Museum of Northern Arizona: Phoenix, Arizona, Museum of Northern Arizona, 67 p.}"
}

ABSTRACT Sixteen separate delta lobes have been formed by the Mississippi River in the past 6,000 years. Fourteen are included in the Teche, St. Bernard, and Lafourche delta complexes; the remaining two include the present birdfoot delta, which is an extension of the earlier formed initial lobe of the Plaquemines-Modern complex. Each delta complex is genetically related to a major Mississippi River course. Individual delta lobes within each complex are the result of the successive distributary networks of a major river course. Delta lobes were defined by detailed facies analyses of sediment cores from hundreds of shallow borings combined with lithologic and faunal data from several hundred additional borings. Each lobe consists of a basal fine-grained prodelta facies, an overlying sandy delta-front facies, and uppermost fine-grained delta-plain facies. The latter deposits include peat accumulations and nonorganic floodplain and natural-levee deposits. More than one hundred radiocarbon age determinations made on discrete delta-plain peats have been used to establish the chronology of the 16 delta lobes. These data, together with the facies relationships, indicate that the development of each delta complex was not a continual process; instead, river shifting from one major course to another caused the temporary cessation of development in one delta complex as progradation occurred in another. Similar deltaic sequences, prevalent in Tertiary outcrops along the northern flank of the Gulf Coast geosyncline, extend basinward as massive subsurface clastic wedges which constitute a major portion of the peripheral basin fill.

@article{openalexw1592594904,
    author = "Frazier, David E.",
    title = "Recent Deltaic Deposits of the Mississippi River: Their Development and Chronology",
    year = "1967",
    abstract = "ABSTRACT Sixteen separate delta lobes have been formed by the Mississippi River in the past 6,000 years. Fourteen are included in the Teche, St. Bernard, and Lafourche delta complexes; the remaining two include the present birdfoot delta, which is an extension of the earlier formed initial lobe of the Plaquemines-Modern complex. Each delta complex is genetically related to a major Mississippi River course. Individual delta lobes within each complex are the result of the successive distributary networks of a major river course. Delta lobes were defined by detailed facies analyses of sediment cores from hundreds of shallow borings combined with lithologic and faunal data from several hundred additional borings. Each lobe consists of a basal fine-grained prodelta facies, an overlying sandy delta-front facies, and uppermost fine-grained delta-plain facies. The latter deposits include peat accumulations and nonorganic floodplain and natural-levee deposits. More than one hundred radiocarbon age determinations made on discrete delta-plain peats have been used to establish the chronology of the 16 delta lobes. These data, together with the facies relationships, indicate that the development of each delta complex was not a continual process; instead, river shifting from one major course to another caused the temporary cessation of development in one delta complex as progradation occurred in another. Similar deltaic sequences, prevalent in Tertiary outcrops along the northern flank of the Gulf Coast geosyncline, extend basinward as massive subsurface clastic wedges which constitute a major portion of the peripheral basin fill.",
    url = "https://openalex.org/W1592594904",
    openalex = "W1592594904"
}

@misc{schumm1967meander16,
    author = "Schumm, S. A",
    title = "Meander wavelength of alluvial rivers",
    year = "1967",
    howpublished = "Science, v. 157, p. 1549-1550",
    note = "talkorigins\_source = {true}; raw\_reference = {Schumm, S. A., 1967, Meander wavelength of alluvial rivers: Science, v. 157, p. 1549-1550.}"
}

@misc{schumm1968river17,
    author = "Schumm, S. A",
    title = "River adjustment to altered hydrologic regimen, Murrumbidgee River and paleochannels, Australia",
    year = "1968",
    howpublished = "United States Geological Survey, Professional Paper, v. 598",
    note = "talkorigins\_source = {true}; raw\_reference = {Schumm, S. A., 1968, River adjustment to altered hydrologic regimen, Murrumbidgee River and paleochannels, Australia: United States Geological Survey, Professional Paper, v. 598.}"
}

@misc{shepard1972incised19,
    author = "Shepard, R. G",
    title = "Incised river meanders",
    year = "1972",
    howpublished = "evolution in simulated bedrock: Science, v. 178, p. 409-411",
    note = "talkorigins\_source = {true}; raw\_reference = {Shepard, R. G., 1972, Incised river meanders: evolution in simulated bedrock: Science, v. 178, p. 409-411.}"
}

@inproceedings{gardner1975the8,
    author = "Gardner, T. W",
    title = "The history of part of the Colorado River and its rivers",
    year = "1975",
    booktitle = "an experimental study: Four Corners Gelogical Society Guidebook, v. 9th Field Conference, p. 87-95",
    note = "talkorigins\_source = {true}; raw\_reference = {Gardner, T. W., 1975, The history of part of the Colorado River and its rivers: an experimental study: Four Corners Gelogical Society Guidebook, v. 9th Field Conference, p. 87-95.}"
}

@book{schumm1977the18,
    author = "Schumm, S. A",
    title = "The Fluvial System",
    year = "1977",
    publisher = "New York, John Wiley \& Sons, 338 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Schumm, S. A., 1977, The Fluvial System: New York, John Wiley \& Sons, 338 p.}"
}

@misc{crossref1978the,
    title = "The Mississippi River Valley alluvial aquifer in Mississippi",
    year = "1978",
    url = "https://doi.org/10.3133/wri78106",
    doi = "10.3133/wri78106",
    openalex = "W2253349364"
}

@misc{smart1979determinism20,
    author = "Smart, J. S",
    title = "Determinism and randomness in fluvial geomorphology",
    year = "1979",
    howpublished = "Eos, v. 60, no. 36, p. 651-655",
    note = "talkorigins\_source = {true}; raw\_reference = {Smart, J. S., 1979, Determinism and randomness in fluvial geomorphology: Eos, v. 60, no. 36, p. 651-655.}"
}

Instability of the alternate-bar type in straight channels has long been identified as the cause of fluvial meandering. The condition of inerodible sidewalls, however, does not allow a meandering channel to develop. Herein a stability analysis of a sinuous channel with erodible banks allows for delineation of a ‘bend’ instability that does not occur in straight channels, and differs from the alternate-bar instability. In the case of alluvial meanders, the two mechanisms are shown to operate at similar characteristic wavelengths. This provides a rationale for the continuous evolution of alternate bars into true bends such that each bend contains one alternate bar. The same bend instability applies to incised meanders. A mechanism for incised alternate bars which differs from that for the alluvial case appears to operate at different characteristic wavelengths than that of bend instability. Analysis of data suggests that meandering in supraglacial meltwater streams is primarily due to the alternate bar mechanism, whereas the meandering of rills incised in cohesive material and of caves is likely due to the bend mechanism. The meander wavelength of incised reaches of meandering streams is often longer than that of adjacent alluvial reaches. An explanation is offered in terms of bend instability.

@article{doi101017s0022112081000451,
    author = "IKEDA, Syunsuke and Parker, Gary and Sawai, Kenji",
    title = "Bend theory of river meanders. Part 1. Linear development",
    year = "1981",
    journal = "Journal of Fluid Mechanics",
    abstract = "Instability of the alternate-bar type in straight channels has long been identified as the cause of fluvial meandering. The condition of inerodible sidewalls, however, does not allow a meandering channel to develop. Herein a stability analysis of a sinuous channel with erodible banks allows for delineation of a ‘bend’ instability that does not occur in straight channels, and differs from the alternate-bar instability. In the case of alluvial meanders, the two mechanisms are shown to operate at similar characteristic wavelengths. This provides a rationale for the continuous evolution of alternate bars into true bends such that each bend contains one alternate bar. The same bend instability applies to incised meanders. A mechanism for incised alternate bars which differs from that for the alluvial case appears to operate at different characteristic wavelengths than that of bend instability. Analysis of data suggests that meandering in supraglacial meltwater streams is primarily due to the alternate bar mechanism, whereas the meandering of rills incised in cohesive material and of caves is likely due to the bend mechanism. The meander wavelength of incised reaches of meandering streams is often longer than that of adjacent alluvial reaches. An explanation is offered in terms of bend instability.",
    url = "https://doi.org/10.1017/s0022112081000451",
    doi = "10.1017/s0022112081000451",
    openalex = "W2105947728"
}

Sediment supplied to the Colorado River within the Grand Canyon has been sorted into distinct deposits of three grain size ranges. The major rapids are formed by boulder deposits from side-canyon tributaries. As a result of a fourfold reduction in peak discharge when Glen Canyon Dam was closed in 1963, new fan debris may increase the gradient through some of the rapids by a factor of 1.8. Cobbles and gravel, transported only during flood stages, are preferentially deposited in the wider sections of the river as bars and riffles and are, for the most part, inactive during post-dam discharges. Fine-grain (largely sandy) terraces occur throughout the canyon, especially along the banks of the large reverse eddies above and below the rapids. The lower terraces are being reworked into beach-like shores by diurnally-varying, post-dam discharges. A slight net lateral erosion of the terraces has resulted. Prior to construction of the dam, sandy bed deposits underwent scour averaging about 1 m during spring floods, balanced by deposition from tributary sources during the summer. Downstream from rapids, decreased turbulence due to lower discharges has resulted in deposition averaging 2.2 m on the bed within the upper portions of the canyon. Differences in rock types along the river determine overall channel morphology. Rocks of low resistance result in a wide valley, a meandering channel, and abundant cobble bars and sand terraces. Narrow channels with rapids and deep pools are most frequent within the sections of the canyon where Precambrian crystalline rocks dominate.

@article{doi101086628592,
    author = "Howard, A. D. and Dolan, Robert",
    title = "Geomorphology of the Colorado River in the Grand Canyon",
    year = "1981",
    journal = "The Journal of Geology",
    abstract = "Sediment supplied to the Colorado River within the Grand Canyon has been sorted into distinct deposits of three grain size ranges. The major rapids are formed by boulder deposits from side-canyon tributaries. As a result of a fourfold reduction in peak discharge when Glen Canyon Dam was closed in 1963, new fan debris may increase the gradient through some of the rapids by a factor of 1.8. Cobbles and gravel, transported only during flood stages, are preferentially deposited in the wider sections of the river as bars and riffles and are, for the most part, inactive during post-dam discharges. Fine-grain (largely sandy) terraces occur throughout the canyon, especially along the banks of the large reverse eddies above and below the rapids. The lower terraces are being reworked into beach-like shores by diurnally-varying, post-dam discharges. A slight net lateral erosion of the terraces has resulted. Prior to construction of the dam, sandy bed deposits underwent scour averaging about 1 m during spring floods, balanced by deposition from tributary sources during the summer. Downstream from rapids, decreased turbulence due to lower discharges has resulted in deposition averaging 2.2 m on the bed within the upper portions of the canyon. Differences in rock types along the river determine overall channel morphology. Rocks of low resistance result in a wide valley, a meandering channel, and abundant cobble bars and sand terraces. Narrow channels with rapids and deep pools are most frequent within the sections of the canyon where Precambrian crystalline rocks dominate.",
    url = "https://doi.org/10.1086/628592",
    doi = "10.1086/628592",
    openalex = "W1984213129"
}

This study describes changes in mean channel-bed elevation, channel width, bed-material sizes, vegetation, water discharges, and sediment loads downstream from 21 dams constructed on alluvial rivers. Most of the studied channels are in the semiarid western United States. Flood peaks generally were decreased by the dams, but in other respects the post-dam water-discharge characteristics varied from river to river. Sediment concentrations and suspended loads were decreased markedly for hundreds of kilometers downstream from dams; post-dam annual sediment loads on some rivers did not equal pre-dam loads anywhere downstream from a dam. Bed degradation varied from negligible to about 7.5 meters in the 287 cross sections studied. In general, most degradation occurred during the first decade or two after dam closure. Bed material initially coarsened as degradation proceeded, but this pattern may change during later years. Channel width can increase, decrease, or remain constant in the reach downstream from a dam. Despite major variation, changes at a cross section in streambed elevation and in channel width with time often can be described by simple hyperbolic equations. Equation coefficients need to be determined empirically. Riparian vegetation commonly increased in the reach downstream from the dams, probably because of the decrease in peak flows.

@article{doi103133pp1286,
    author = "Williams, Garnett P. and Wolman, M. Gordon",
    title = "Downstream effects of dams on alluvial rivers",
    year = "1984",
    journal = "USGS professional paper",
    abstract = "This study describes changes in mean channel-bed elevation, channel width, bed-material sizes, vegetation, water discharges, and sediment loads downstream from 21 dams constructed on alluvial rivers. Most of the studied channels are in the semiarid western United States. Flood peaks generally were decreased by the dams, but in other respects the post-dam water-discharge characteristics varied from river to river. Sediment concentrations and suspended loads were decreased markedly for hundreds of kilometers downstream from dams; post-dam annual sediment loads on some rivers did not equal pre-dam loads anywhere downstream from a dam. Bed degradation varied from negligible to about 7.5 meters in the 287 cross sections studied. In general, most degradation occurred during the first decade or two after dam closure. Bed material initially coarsened as degradation proceeded, but this pattern may change during later years. Channel width can increase, decrease, or remain constant in the reach downstream from a dam. Despite major variation, changes at a cross section in streambed elevation and in channel width with time often can be described by simple hyperbolic equations. Equation coefficients need to be determined empirically. Riparian vegetation commonly increased in the reach downstream from the dams, probably because of the decrease in peak flows.",
    url = "https://doi.org/10.3133/pp1286",
    doi = "10.3133/pp1286",
    openalex = "W1557871810",
    references = "doi101002esp3290030207, doi1010079781468486131, doi1010160037073869900104, doi101029tr035i006p00951, doi101029tr039i006p01076, doi101086628592, doi101177030913337900300302, doi1023071793758, doi1023071942394, openalexw2565754195"
}

A proposed navigation project on the Yazoo River between Vicksburg and Greenwood, Mississippi, will increase minimum river stages by more than 19 feet at the site of the proposed lock and dam near Vicksburg, and will decrease minimum river stages by 2 to 7 feet in much of the upper reach of the river. Water-level data for 65 observation wells in the alluvial aquifer in the vicinity of the proposed project indicate that post-project minimum ground-water levels in wells very near the river will range from more than 19 feet higher than pre-project minimum levels near Vicksburg to about 7 feet lower than pre-project levels at Greenwood. Post-project ground-water levels will generally be between 15 and 25 feet below land surface during the dry season but will be at or near land surface during the wet season. The change in ground-water levels will decrease with distance from the river but may extend as far as the Bluff Hills to the east and the auxiliary channel or other major drainage features to the west. In the upper reach of the river the decrease in ground-water levels may extend beyond the auxiliary channel to the areas of large ground-water withdrawals several miles to the west of the river. (USGS)

@misc{doi103133wri844039,
    author = "Lamonds, A.G. and Kernodle, J.M.",
    title = "Potential ground-water level changes in the Mississippi River alluvial aquifer in response to proposed navigation improvements on the Yazoo River in Mississippi",
    year = "1984",
    abstract = "A proposed navigation project on the Yazoo River between Vicksburg and Greenwood, Mississippi, will increase minimum river stages by more than 19 feet at the site of the proposed lock and dam near Vicksburg, and will decrease minimum river stages by 2 to 7 feet in much of the upper reach of the river. Water-level data for 65 observation wells in the alluvial aquifer in the vicinity of the proposed project indicate that post-project minimum ground-water levels in wells very near the river will range from more than 19 feet higher than pre-project minimum levels near Vicksburg to about 7 feet lower than pre-project levels at Greenwood. Post-project ground-water levels will generally be between 15 and 25 feet below land surface during the dry season but will be at or near land surface during the wet season. The change in ground-water levels will decrease with distance from the river but may extend as far as the Bluff Hills to the east and the auxiliary channel or other major drainage features to the west. In the upper reach of the river the decrease in ground-water levels may extend beyond the auxiliary channel to the areas of large ground-water withdrawals several miles to the west of the river. (USGS)",
    url = "https://doi.org/10.3133/wri844039",
    doi = "10.3133/wri844039",
    openalex = "W96254312",
    references = "crossref1978the, doi103133ofr791585, doi103133ofr811123, doi103133pp448i"
}

The 7,000 square-mile Mississippi River alluvial plain in north-western Mississippi (the Delta) is underlain by the prolific Mississippi River alluvial aquifer that currently (1983) yields about 1,100 Mgal/d of water to irrigation wells. Commonly, about 20 feet of clay underlying the Delta land surface is underlain by about 80 to 180 feet of sand and gravel that forms the aquifer. The Mississippi River is in good hydraulic connection with the alluvial aquifer. Generally smaller streams are less likely to have good hydraulic connection with the aquifer. Direct vertical recharge to the alluvial aquifer is small. A two-dimensional finite-difference computer model of the alluvial aquifer was constructed, calibrated, and verified using water levels observed for five dates within the period April 1981 to September 1983. The model shows that the aquifer had a net loss in storage of about 360 Mgal/d for the 2-year period April 1981 to April 1983, when pumpage was about 1,100 Mgal/d. The net inflows from the sources of recharge were: Mississippi River, 390 Mgal/d; recharge along east edge of the Delta, 170 Mgal/d; streams within the Delta, 81 Mgal/d; and areal recharge from infiltration, 180 Mgal/d. The effects of several levels of pumpage by wells were projected 20 years into the future. In 2003, the result of continued pumpage at the 1,100 Mgal/d pumping rate would be lowered ground-water levels of more than 20 feet in a large area in the central part of the Delta, and ground-water levels would continue to decline. (USGS)

@misc{doi103133wri844343,
    author = "Sumner, David M. and Wasson, B.E.",
    title = "Summary of results of an investigation to define the geohydrology and simulate the effects of large ground-water withdrawals on the Mississippi River alluvial aquifer in northwestern Mississippi",
    year = "1984",
    abstract = "The 7,000 square-mile Mississippi River alluvial plain in north-western Mississippi (the Delta) is underlain by the prolific Mississippi River alluvial aquifer that currently (1983) yields about 1,100 Mgal/d of water to irrigation wells. Commonly, about 20 feet of clay underlying the Delta land surface is underlain by about 80 to 180 feet of sand and gravel that forms the aquifer. The Mississippi River is in good hydraulic connection with the alluvial aquifer. Generally smaller streams are less likely to have good hydraulic connection with the aquifer. Direct vertical recharge to the alluvial aquifer is small. A two-dimensional finite-difference computer model of the alluvial aquifer was constructed, calibrated, and verified using water levels observed for five dates within the period April 1981 to September 1983. The model shows that the aquifer had a net loss in storage of about 360 Mgal/d for the 2-year period April 1981 to April 1983, when pumpage was about 1,100 Mgal/d. The net inflows from the sources of recharge were: Mississippi River, 390 Mgal/d; recharge along east edge of the Delta, 170 Mgal/d; streams within the Delta, 81 Mgal/d; and areal recharge from infiltration, 180 Mgal/d. The effects of several levels of pumpage by wells were projected 20 years into the future. In 2003, the result of continued pumpage at the 1,100 Mgal/d pumping rate would be lowered ground-water levels of more than 20 feet in a large area in the central part of the Delta, and ground-water levels would continue to decline. (USGS)",
    url = "https://doi.org/10.3133/wri844343",
    doi = "10.3133/wri844343",
    openalex = "W203807141",
    references = "crossref1978the, doi103133ofr83875, doi103133wsp2292"
}

@misc{crossref1985floodflow,
    title = "Floodflow frequency of streams in the alluvial plain of the Lower Mississippi River in Mississippi, Arkansas, and Louisiana",
    year = "1985",
    url = "https://doi.org/10.3133/wri854150",
    doi = "10.3133/wri854150",
    openalex = "W1548440186",
    references = "doi102307211375, doi10313325250, doi103133wsp1677"
}

Abstract The Tertiary Fort Union and Wasatch formations in the Powder River Basin contain economic coal and uranium deposits that are targets for exploration and development. These activities have provided considerable subsurface and surface data that were used to analyze the evolution of depositional systems in the basin. The Paleocene Fort Union Formation consists, in ascending order, of the Tullock, Lebo Shale and Tongue River Members. The Eocene Wasatch Formation consists of the conglomeratic Kingsbury and Moncrief Members and laterally equivalent finer grained deposits. Both formations contain sandstone, conglomerate, siltstone, mudstone, limestone, carbonaceous shale, and coal. The high proportion of sandstones in the Tullock Member and combined Tongue River Member of the Fort Union Formation and Wasatch Formation generally occurs in interconnected east-west and north-south belts. East-west belts probably represent deposits from alluvial fan and braided and meandering tributary streams. North-south belts probably represent deposits from meandering and anastomosing trunk streams fed by basin margin tributaries. The sandstones of the Lebo Shale Member generally show east-west trends and probably represent deposits of fluvio-deltaic systems that fed a closed lacustrine basin. Lake formation may have been promoted by localized subsidence along the Buffalo Deep Fault. These contrasting styles of fluvial deposition were largely controlled by extrabasinal and intrabasinal tectonics during the Laramide orogeny. Comparison of the distribution of sandstone belts in the Powder River Basin with modern fluvial analogues indicates similarities with the following trunk-tributary fluvial systems: the Mahakam River in the Kutai Basin, Borneo; Rio Paraiba do Sul in the State of Sao Paulo, Brazil; and Lower Saskatchewan River, Canada. These fluvial systems consist of mixed-load meandering and anastomosing streams that drain alluvial plains in an intermontane or continental setting.

@article{s2f99bbfa8c30830a7860eba91267f7583efbca4c3,
    author = "Flores, R. and Ethridge, F.",
    title = "Evolution of Intermontane Fluvial Systems of Tertiary Powder River Basin, Montana and Wyoming",
    year = "1985",
    abstract = "Abstract The Tertiary Fort Union and Wasatch formations in the Powder River Basin contain economic coal and uranium deposits that are targets for exploration and development. These activities have provided considerable subsurface and surface data that were used to analyze the evolution of depositional systems in the basin. The Paleocene Fort Union Formation consists, in ascending order, of the Tullock, Lebo Shale and Tongue River Members. The Eocene Wasatch Formation consists of the conglomeratic Kingsbury and Moncrief Members and laterally equivalent finer grained deposits. Both formations contain sandstone, conglomerate, siltstone, mudstone, limestone, carbonaceous shale, and coal. The high proportion of sandstones in the Tullock Member and combined Tongue River Member of the Fort Union Formation and Wasatch Formation generally occurs in interconnected east-west and north-south belts. East-west belts probably represent deposits from alluvial fan and braided and meandering tributary streams. North-south belts probably represent deposits from meandering and anastomosing trunk streams fed by basin margin tributaries. The sandstones of the Lebo Shale Member generally show east-west trends and probably represent deposits of fluvio-deltaic systems that fed a closed lacustrine basin. Lake formation may have been promoted by localized subsidence along the Buffalo Deep Fault. These contrasting styles of fluvial deposition were largely controlled by extrabasinal and intrabasinal tectonics during the Laramide orogeny. Comparison of the distribution of sandstone belts in the Powder River Basin with modern fluvial analogues indicates similarities with the following trunk-tributary fluvial systems: the Mahakam River in the Kutai Basin, Borneo; Rio Paraiba do Sul in the State of Sao Paulo, Brazil; and Lower Saskatchewan River, Canada. These fluvial systems consist of mixed-load meandering and anastomosing streams that drain alluvial plains in an intermontane or continental setting.",
    url = "https://www.semanticscholar.org/paper/f99bbfa8c30830a7860eba91267f7583efbca4c3",
    is_oa = "true",
    openalex = "W2242903004",
    semanticscholar_citation_count = "40",
    semanticscholar_id = "f99bbfa8c30830a7860eba91267f7583efbca4c3"
}

The Gulf Coast Regional Aquifer-System Analysis is a study of regional aquifers in sediments of mostly Cenozoic age in an area of about 230,000 sq mi in the Central Plain of Alabama, Arkansas, Florida, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas, and an additional 60,000 sq mi offshore. Three aquifer systems have been identified: the Mississippi embayment aquifer system, the Texas coastal uplands aquifer system, and the coastal lowlands aquifer system. These aquifer systems thicken from < 100 ft near their updip limit to thousands of ft gulfward toward their downdip limits. The Mississippi embayment aquifer system exceeds 5,000 ft in thickness in central Louisiana and in southwestern Mississippi. The thickest area in southwestern Mississippi underlies most of the six Mississippi counties, centered around Jefferson County. The greatest thickness of the coastal lowlands aquifer system in Mississippi occurs in southern Hancock County where the system is composed of several individual aquifers and confining units. There are seven aquifers and three confining units in the Mississippi embayment aquifer system, five aquifers and two confining units in the Texas coastal uplands aquifer system, and five aquifers and two confining units in the coastal lowlands aquifer system. Most of the thicker parts of each aquifer system contain moderately saline to very saline water. Water in the Mississippi embayment aquifer system is moderately saline to very saline in most of a seven county area in southwestern Mississippi. About 9,600 million gal/day (gpd) of ground water was pumped from the aquifers in the study area during 1980. About 15% of that pumpage (or about 1,400 million gpd was in Mississippi, mostly from the Mississippi River Valley alluvial aquifer of the Mississippi embayment aquifer system. About 10% of the Mississippi pumpage, or 140 million gpd, was from the coastal lowlands aquifer system. Preliminary results from simulation of groundwater flow indicates that parts of Mississippi are major regional recharge areas for both the Mississippi embayment aquifer system and the coastal lowlands aquifer system.

@misc{doi103133wri864162,
    author = "Grubb, Hayes F.",
    title = "Gulf Coast Regional Aquifer-System Analysis — A Mississippi perspective",
    year = "1986",
    abstract = "The Gulf Coast Regional Aquifer-System Analysis is a study of regional aquifers in sediments of mostly Cenozoic age in an area of about 230,000 sq mi in the Central Plain of Alabama, Arkansas, Florida, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas, and an additional 60,000 sq mi offshore. Three aquifer systems have been identified: the Mississippi embayment aquifer system, the Texas coastal uplands aquifer system, and the coastal lowlands aquifer system. These aquifer systems thicken from < 100 ft near their updip limit to thousands of ft gulfward toward their downdip limits. The Mississippi embayment aquifer system exceeds 5,000 ft in thickness in central Louisiana and in southwestern Mississippi. The thickest area in southwestern Mississippi underlies most of the six Mississippi counties, centered around Jefferson County. The greatest thickness of the coastal lowlands aquifer system in Mississippi occurs in southern Hancock County where the system is composed of several individual aquifers and confining units. There are seven aquifers and three confining units in the Mississippi embayment aquifer system, five aquifers and two confining units in the Texas coastal uplands aquifer system, and five aquifers and two confining units in the coastal lowlands aquifer system. Most of the thicker parts of each aquifer system contain moderately saline to very saline water. Water in the Mississippi embayment aquifer system is moderately saline to very saline in most of a seven county area in southwestern Mississippi. About 9,600 million gal/day (gpd) of ground water was pumped from the aquifers in the study area during 1980. About 15\% of that pumpage (or about 1,400 million gpd was in Mississippi, mostly from the Mississippi River Valley alluvial aquifer of the Mississippi embayment aquifer system. About 10\% of the Mississippi pumpage, or 140 million gpd, was from the coastal lowlands aquifer system. Preliminary results from simulation of groundwater flow indicates that parts of Mississippi are major regional recharge areas for both the Mississippi embayment aquifer system and the coastal lowlands aquifer system.",
    url = "https://doi.org/10.3133/wri864162",
    doi = "10.3133/wri864162",
    openalex = "W169948734",
    references = "crossref1978the, doi101029wr003i002p00623, doi101029wr019i001p00234, doi1023071788077, doi103133cir456, doi103133pp448c, doi103133pp448e, doi103133pp569a, doi103133pp569d, doi103133wri844219, doi103133wsp1364"
}

This detailed study of the sedimentology and facies architecture of three overbank subenvironments which occur marginal to a meander belt in the lower Mississippi River Valley leads to the following conclusions: 1) backswamp, levee and splay deposits can be subdivided into units related to the establishment of the associated channel belt; 2) cycles related to avulsion, levee progradation, splay progradation and abandonment, and sheet-flood events are preserved in flood basin deposits; and 3) flood basin facies prograde basinward as the levee builds upward over time along a channel belt margin. The establishment of the channel belt is divided into four phases: 1) a pre-avulsion stage, 2) an avulsion stage, 3) an early channel belt, and 4) a late channel belt stage. In the study area, the flood basin sequence affiliated with the avulsion and establishment of the channel belt (30 m) has a maximum thickness of about 10 m. The avulsion event is probably recorded in the sedimentary sequence as the lithologic change from blue clay with detrital organie debris deposited in standing water to sheet-flood silts and sands related to levee and splay progradation during incipient formation of the channel belt. Surficial levee deposits (silty sand unit) exhibit an overall coarsening-upward sequence (2.5 m) that reflects meander bend migration toward the sampling site during the late stage of channel belt development. Surficial splay deposits (silty sand unit) initially coarsen upward during the progradational phase and then fine upward as the splay is abandoned (3 m). Individual flood cycles (mm-cm) occur as small-scale fining-upward rhythmites with poorly preserved stratification in all sub-environments.

@incollection{doi102110pec87390111,
    author = "Farrell, Kathleen M.",
    title = "SEDIMENTOLOGY AND FACIES ARCHITECTURE OF OVERBANK DEPOSITS OF THE MISSISSIPPI RIVER, FALSE RIVER REGION, LOUISIANA",
    year = "1987",
    booktitle = "SEPM (Society for Sedimentary Geology) eBooks",
    abstract = "This detailed study of the sedimentology and facies architecture of three overbank subenvironments which occur marginal to a meander belt in the lower Mississippi River Valley leads to the following conclusions: 1) backswamp, levee and splay deposits can be subdivided into units related to the establishment of the associated channel belt; 2) cycles related to avulsion, levee progradation, splay progradation and abandonment, and sheet-flood events are preserved in flood basin deposits; and 3) flood basin facies prograde basinward as the levee builds upward over time along a channel belt margin. The establishment of the channel belt is divided into four phases: 1) a pre-avulsion stage, 2) an avulsion stage, 3) an early channel belt, and 4) a late channel belt stage. In the study area, the flood basin sequence affiliated with the avulsion and establishment of the channel belt (30 m) has a maximum thickness of about 10 m. The avulsion event is probably recorded in the sedimentary sequence as the lithologic change from blue clay with detrital organie debris deposited in standing water to sheet-flood silts and sands related to levee and splay progradation during incipient formation of the channel belt. Surficial levee deposits (silty sand unit) exhibit an overall coarsening-upward sequence (2.5 m) that reflects meander bend migration toward the sampling site during the late stage of channel belt development. Surficial splay deposits (silty sand unit) initially coarsen upward during the progradational phase and then fine upward as the splay is abandoned (3 m). Individual flood cycles (mm-cm) occur as small-scale fining-upward rhythmites with poorly preserved stratification in all sub-environments.",
    url = "https://doi.org/10.2110/pec.87.39.0111",
    doi = "10.2110/pec.87.39.0111",
    openalex = "W1539037061"
}

ABSTRACT A geomorphic and stratigraphic investigation of lacustrine delta deposits in the Atchafalaya Basin, Louisiana, revealed that lacustrine delta formation is rapid and cyclic in nature. During the Holocene, thin, coarse-grained, regionally extensive, fluvially dominated lacustrine deltas filled interdistributary basins in the transition zone between the alluvial valley and the marine delta plain of the Mississippi River. One delta, Lake Fausse Pointe delta, prograded 6.5 km, partially filling the lake and covering more than 29 km2 in area in twelve years. Depositional processes in Lake Fausse Pointe ranged from suspension-settling of mud and organic matter during low sediment input to traction deposition of sand during floods. Hyperpycnal flow conditions, set up by the introdu tion of sediment-laden river water into the freshwater lake, induced underflows that scoured the lake bottom and deposited upward-coarsening lobes. The low relief of the Mississippi basin, a constant large volume of fine-grained sediment supply, and prevalent fluvial processes have formed fluvially dominated lacustrine deltas that differ sedimentologically and stratigraphically from Gilbert-type and brackish-water lacustrine deltas. Parallel-laminated prodelta mud, rippled to cross-laminated delta-front silty sand, and very finegrained to medium-grained distributary-mouth-bar sand are characteristic of rapidly deposited sediment, whereas rooted and burrowed sediments signify periods of minimal deposition. In a fluvially dominated setting, delta geometry and sediment distribution patterns are controlled by river-mouth processes, basin shape, and bathymetry. Thickest sand accumulations occur in linear, dip-elongate distributary-m uth-bar and natural-levee lobes that are separated laterally by mud-filled channels and interdistributary troughs. Lacustrine-delta deposition is driven by basin subsidence (regional downwarping and sediment compaction) and the concomitant development of distributary channels in the interdistributary basins. Numerous lacustrine-deltaic wedges, each bounded by rooted backswamp clay, are preserved multilaterally in Atchafalaya Basin sediments. Although lacustrine-deltaic deposits constitute much of the basin's sedimentary fill, each individual delta sequence records depositional events of only 100 years duration. These deltaic deposits represent basin-filling (aggradational) episodes that preceded the formation of marine delta complexes such as the Maringouin, Teche, La Fourche, and Atchafalaya deltas of the Mississippi River.

@article{doi101306212f90ca2b2411d78648000102c1865d,
    author = "Tye, Robert S.",
    title = "Depositional Processes and Stratigraphy of Fluvially Dominated Lacustrine Deltas: Mississippi Delta Plain",
    year = "1989",
    journal = "Journal of Sedimentary Research",
    abstract = "ABSTRACT A geomorphic and stratigraphic investigation of lacustrine delta deposits in the Atchafalaya Basin, Louisiana, revealed that lacustrine delta formation is rapid and cyclic in nature. During the Holocene, thin, coarse-grained, regionally extensive, fluvially dominated lacustrine deltas filled interdistributary basins in the transition zone between the alluvial valley and the marine delta plain of the Mississippi River. One delta, Lake Fausse Pointe delta, prograded 6.5 km, partially filling the lake and covering more than 29 km2 in area in twelve years. Depositional processes in Lake Fausse Pointe ranged from suspension-settling of mud and organic matter during low sediment input to traction deposition of sand during floods. Hyperpycnal flow conditions, set up by the introdu tion of sediment-laden river water into the freshwater lake, induced underflows that scoured the lake bottom and deposited upward-coarsening lobes. The low relief of the Mississippi basin, a constant large volume of fine-grained sediment supply, and prevalent fluvial processes have formed fluvially dominated lacustrine deltas that differ sedimentologically and stratigraphically from Gilbert-type and brackish-water lacustrine deltas. Parallel-laminated prodelta mud, rippled to cross-laminated delta-front silty sand, and very finegrained to medium-grained distributary-mouth-bar sand are characteristic of rapidly deposited sediment, whereas rooted and burrowed sediments signify periods of minimal deposition. In a fluvially dominated setting, delta geometry and sediment distribution patterns are controlled by river-mouth processes, basin shape, and bathymetry. Thickest sand accumulations occur in linear, dip-elongate distributary-m uth-bar and natural-levee lobes that are separated laterally by mud-filled channels and interdistributary troughs. Lacustrine-delta deposition is driven by basin subsidence (regional downwarping and sediment compaction) and the concomitant development of distributary channels in the interdistributary basins. Numerous lacustrine-deltaic wedges, each bounded by rooted backswamp clay, are preserved multilaterally in Atchafalaya Basin sediments. Although lacustrine-deltaic deposits constitute much of the basin's sedimentary fill, each individual delta sequence records depositional events of only 100 years duration. These deltaic deposits represent basin-filling (aggradational) episodes that preceded the formation of marine delta complexes such as the Maringouin, Teche, La Fourche, and Atchafalaya deltas of the Mississippi River.",
    url = "https://doi.org/10.1306/212f90ca-2b24-11d7-8648000102c1865d",
    doi = "10.1306/212f90ca-2b24-11d7-8648000102c1865d",
    openalex = "W2112365365"
}

1. Rivers: environment, process and form: Keith S.Richards (Department of Geography, University of Cambridge) 2. Spatial adjustments to temporal variations in flood regime in some Australian rivers: Robin F.Warner (Department of Geography, University of Sydney) 3. The effect of active tectonics on alluvial river morphology: Daniel I.Gregory (Water Engineering and Technology Inc., Colorado) and Stanley A.Schumm (Department of Earth Sciences, Colorado State University) 4. Modelling fluvial systems: rock, gravel and sand bed channels: Alan D.Howard (Department of Environmental Science, University of Virginia) 5. River Channel adjustment - the downstream dimension: D.Knighton (Department of Geography, University of Sheffield) 6. Hydraulic and sedimentary controls of channel pattern: Rob Ferguson (Department of Environmental Science, University of Stirling) 7. Bed forms and clast size changes in gravel bed rivers: B.J.Bluck: (Department of Geology, University of Glasgow) 8. Mechanics of flow and sediment transport in river bends: William E.Dietrich (Department of Geology and Geophysics, University of California) 9. Channel boundary shape - evolution and equilibrium: T.R.H. Davies (Agricultural Engineering Department, Lincoln College, Canterbury) 10. Small and medium scale bedforms in gravel bed rivers: Pamela S.Naden (School of Geography, Leeds University) and Andrew C.Brayshaw (BP PLC, Brittanic House) 11. Measuring and modelling bedload transport in channels with coarse bed materials: James C.Bathurst (NERC Water Resource Systems Research Unit, Department of Civil Engineering, University of Newcastle-upon-Tyne) 12. The classification and characterization of rivers: M.P.Mosley (Ministry of Works and Development, New Zealand) 13. Bed stability in gravel streams, with reference to stream regulation and ecology: P.A.Carling (Freshwater Biological Association, Cumbria) 14. Applied fluvial geomorphology: river engineering project appraisal in its geomorphological context: K.S.Richards, (Department of Geography, University of Cambridge) with D.Brunsden, (Department of Geography, King's College London) D.K.C.Jones, (Department of Geography, LSE) and M.McCaig (formerly Geomorphological Services Ltd., Bucks.).

@article{doi102307215690,
    author = "Rhoads, Bruce L. and Richards, Keith",
    title = "River Channels: Environment and Process",
    year = "1989",
    journal = "Geographical Review",
    abstract = "1. Rivers: environment, process and form: Keith S.Richards (Department of Geography, University of Cambridge) 2. Spatial adjustments to temporal variations in flood regime in some Australian rivers: Robin F.Warner (Department of Geography, University of Sydney) 3. The effect of active tectonics on alluvial river morphology: Daniel I.Gregory (Water Engineering and Technology Inc., Colorado) and Stanley A.Schumm (Department of Earth Sciences, Colorado State University) 4. Modelling fluvial systems: rock, gravel and sand bed channels: Alan D.Howard (Department of Environmental Science, University of Virginia) 5. River Channel adjustment - the downstream dimension: D.Knighton (Department of Geography, University of Sheffield) 6. Hydraulic and sedimentary controls of channel pattern: Rob Ferguson (Department of Environmental Science, University of Stirling) 7. Bed forms and clast size changes in gravel bed rivers: B.J.Bluck: (Department of Geology, University of Glasgow) 8. Mechanics of flow and sediment transport in river bends: William E.Dietrich (Department of Geology and Geophysics, University of California) 9. Channel boundary shape - evolution and equilibrium: T.R.H. Davies (Agricultural Engineering Department, Lincoln College, Canterbury) 10. Small and medium scale bedforms in gravel bed rivers: Pamela S.Naden (School of Geography, Leeds University) and Andrew C.Brayshaw (BP PLC, Brittanic House) 11. Measuring and modelling bedload transport in channels with coarse bed materials: James C.Bathurst (NERC Water Resource Systems Research Unit, Department of Civil Engineering, University of Newcastle-upon-Tyne) 12. The classification and characterization of rivers: M.P.Mosley (Ministry of Works and Development, New Zealand) 13. Bed stability in gravel streams, with reference to stream regulation and ecology: P.A.Carling (Freshwater Biological Association, Cumbria) 14. Applied fluvial geomorphology: river engineering project appraisal in its geomorphological context: K.S.Richards, (Department of Geography, University of Cambridge) with D.Brunsden, (Department of Geography, King's College London) D.K.C.Jones, (Department of Geography, LSE) and M.McCaig (formerly Geomorphological Services Ltd., Bucks.).",
    url = "https://doi.org/10.2307/215690",
    doi = "10.2307/215690",
    openalex = "W2011688127"
}

Data describing the aquifer framework and steady-state regional flow were assembled for the Mississippi River Valley alluvial aquifer north of Vicksburg, Mississippi. The aquifer is part of the Mississippi embayment aquifer system. The 60 to 140 ft thick alluvial aquifer grades from gravel at the bottom to fine sand near the top. It is overlain by the Mississippi River Valley confining unit, which consists of 10 to 50 ft of silts, clays, and fine-grained sands. Underlying units consist of alternating sands and clays corresponding to regional hydrogeologic units of the Mississippi embayment aquifer system. The three-layer finite difference model was used to simulate two-dimensional confined or unconfined steady-state flow for predevelopment and 1972. Preliminary analysis of predevelopment flow indicates that recharge to the alluvial aquifer was from underlying aquifers and the confining unit. Rivers accounted for almost all discharge. Pumpage from the alluvial aquifer for irrigation substantially changed regional flow direction toward depressions in the potentiometric surface. Recharge from rivers and the confining unit increased and recharge from underlying aquifers decreased. Discharge to underlying aquifers increased and discharge to rivers decreased. Recharge from the confining unit reached a maximum of 1.3 inch/year for large parts of the aquifer. Nearly all drawdown exceeding 20 ft was at two locations in Arkansas--the Grande Prairie region, and west of Crowleys Ridge. Model results indicate the importance of leakage from rivers and the confining unite to providing recharge to sustain large amounts of pumpage from the alluvial aquifer.

@misc{doi103133wri884028,
    author = "Ackerman, D.J.",
    title = "Hydrology of the Mississippi River Valley alluvial aquifer, south- central United States — A preliminary assessment of the regional flow system",
    year = "1989",
    abstract = "Data describing the aquifer framework and steady-state regional flow were assembled for the Mississippi River Valley alluvial aquifer north of Vicksburg, Mississippi. The aquifer is part of the Mississippi embayment aquifer system. The 60 to 140 ft thick alluvial aquifer grades from gravel at the bottom to fine sand near the top. It is overlain by the Mississippi River Valley confining unit, which consists of 10 to 50 ft of silts, clays, and fine-grained sands. Underlying units consist of alternating sands and clays corresponding to regional hydrogeologic units of the Mississippi embayment aquifer system. The three-layer finite difference model was used to simulate two-dimensional confined or unconfined steady-state flow for predevelopment and 1972. Preliminary analysis of predevelopment flow indicates that recharge to the alluvial aquifer was from underlying aquifers and the confining unit. Rivers accounted for almost all discharge. Pumpage from the alluvial aquifer for irrigation substantially changed regional flow direction toward depressions in the potentiometric surface. Recharge from rivers and the confining unit increased and recharge from underlying aquifers decreased. Discharge to underlying aquifers increased and discharge to rivers decreased. Recharge from the confining unit reached a maximum of 1.3 inch/year for large parts of the aquifer. Nearly all drawdown exceeding 20 ft was at two locations in Arkansas--the Grande Prairie region, and west of Crowleys Ridge. Model results indicate the importance of leakage from rivers and the confining unite to providing recharge to sustain large amounts of pumpage from the alluvial aquifer.",
    url = "https://doi.org/10.3133/wri884028",
    doi = "10.3133/wri884028",
    openalex = "W110423691"
}

Professional Papers are mainly comprehensive scientific reports of wide and lasting interest and importance to professional scientists and engineers. Included are reports on the results of resource studies and of topographic, hydrologic. and geologic investigations. They also include collections of related papers addressing different aspects of a single scientific topic.

@misc{doi103133wsp2292,
    author = "Sumner, D. M. and Wasson, B.E.",
    title = "Geohydrology and simulated effects of large ground-water withdrawals on the Mississippi River alluvial aquifer in northwestern Mississippi",
    year = "1990",
    abstract = "Professional Papers are mainly comprehensive scientific reports of wide and lasting interest and importance to professional scientists and engineers. Included are reports on the results of resource studies and of topographic, hydrologic. and geologic investigations. They also include collections of related papers addressing different aspects of a single scientific topic.",
    url = "https://doi.org/10.3133/wsp2292",
    doi = "10.3133/wsp2292",
    openalex = "W4241248829",
    references = "crossref1978the, doi1023071788077, doi102307211375, doi103133ha516, doi103133ofr83875, doi103133pp448i, doi103133pp708, doi103133wri7717, doi103133wsp1615h, doi103133wsp1619v"
}

As part of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program, the Gulf Coast RASA was initiated to investigate all Tertiary and Quaternary aquifers underlying the Coastal Plain in the south-central United States. Geohydrologic units that make up two of the three regional aquifer systems Mississippi embayment and Texas coastal uplands in the area are described in this report. The gulfward boundary of the outcrop of the two aquifer systems is the southernmost outcrop or subcrop of the Vicksburg-Jackson confining unit, and the updip boundary is the contact between Cretaceous and Tertiary deposits, extending northward to the southern tip of Illinois. The uppermost Cretaceous aquifer, the McNairy-Nacatoch aquifer in the northern part of the Mississippi embayment, is also included where it may be hydraulically connected to the younger sediments. Major regional geohydrologic units generally are coincident with previously defined geologic units. Most of the geohydrologic units consist of alternating sand and clay; however, the entire sequence becomes a clay and carbonate facies gulfward. The regional geohydrologic units delineated in this study, from youngest to oldest, are (1) Mississippi River Valley alluvial aquifer, (2) Vicksburg-Jackson confining unit, (3) upper Claiborne aquifer, (4) middle Claiborne confining unit, (5) middle Claiborne aquifer, (6) lower Claiborne confining unit, (7) lower Claiborne-upper Wilcox aquifer, (8) middle Wilcox aquifer, (9) lower Wilcox aquifer, (10) Midway confining unit, and (11) McNairy-Nacatoch aquifer. The Mississippi embayment aquifer system contains all of these units and has a maximum thickness of about 5,000 feet. The Texas coastal uplands aquifer system, which is contiguous with the Mississippi embayment aquifer system and extends westward and southwestward from the Sabinc uplift, contains all of the foregoing geohydrologic units except the Mississippi River Valley alluvial aquifer, the lower Wilcox aquifer, and the McNairy-Nacatoch aquifer. The Texas coastal uplands aquifer system has a maximum thickness of about 7,000 feet.

@article{doi103133pp1416b,
    author = "Hosman, R.L. and Weiss, Jonathan S.",
    title = "Geohydrologic units of the Mississippi embayment and Texas coastal uplands aquifer systems, south-central United States",
    year = "1991",
    journal = "USGS professional paper",
    abstract = "As part of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program, the Gulf Coast RASA was initiated to investigate all Tertiary and Quaternary aquifers underlying the Coastal Plain in the south-central United States. Geohydrologic units that make up two of the three regional aquifer systems Mississippi embayment and Texas coastal uplands in the area are described in this report. The gulfward boundary of the outcrop of the two aquifer systems is the southernmost outcrop or subcrop of the Vicksburg-Jackson confining unit, and the updip boundary is the contact between Cretaceous and Tertiary deposits, extending northward to the southern tip of Illinois. The uppermost Cretaceous aquifer, the McNairy-Nacatoch aquifer in the northern part of the Mississippi embayment, is also included where it may be hydraulically connected to the younger sediments. Major regional geohydrologic units generally are coincident with previously defined geologic units. Most of the geohydrologic units consist of alternating sand and clay; however, the entire sequence becomes a clay and carbonate facies gulfward. The regional geohydrologic units delineated in this study, from youngest to oldest, are (1) Mississippi River Valley alluvial aquifer, (2) Vicksburg-Jackson confining unit, (3) upper Claiborne aquifer, (4) middle Claiborne confining unit, (5) middle Claiborne aquifer, (6) lower Claiborne confining unit, (7) lower Claiborne-upper Wilcox aquifer, (8) middle Wilcox aquifer, (9) lower Wilcox aquifer, (10) Midway confining unit, and (11) McNairy-Nacatoch aquifer. The Mississippi embayment aquifer system contains all of these units and has a maximum thickness of about 5,000 feet. The Texas coastal uplands aquifer system, which is contiguous with the Mississippi embayment aquifer system and extends westward and southwestward from the Sabinc uplift, contains all of the foregoing geohydrologic units except the Mississippi River Valley alluvial aquifer, the lower Wilcox aquifer, and the McNairy-Nacatoch aquifer. The Texas coastal uplands aquifer system has a maximum thickness of about 7,000 feet.",
    url = "https://doi.org/10.3133/pp1416b",
    doi = "10.3133/pp1416b",
    openalex = "W1561554722"
}

Flood magnitudes for selected recurrence intervals from 2 to 500 years were determined for 330 gaged sites in the study area where annual peak-flow records have been collected. The principal study area is Mississippi; however, selected data collected in adjoining States on streams draining into or from Mississippi are also included, flood frequency at a gaged stream site is defined by fitting the Pearson Type III probability distribution to the log-transformed annual peaks. The accuracy of the flood frequency determined for a gaged site is determined primarily by the number of years of annual peak-flow record (the sample size). Greater accuracy is achieved in the current analysis than in previous analyses because of the additional years of annual peak-flow record. Flood-frequency and basin characteristics at gaged sites were used to develop regression equations for estimating flood frequency where annual peak-flow records are not available.Flood frequency for ungaged stream sites in Mississippi may be estimated using basin characteristics in regression equations. Regression equations were computed using the generalized-least-squares procedure rather than the ordinary-least-squares procedure used in previous regional hydrologic analyses. The generalized-least-squares procedure considers the variable error of the gaging station flood frequencies and corrects for the cross-correlation of concurrent annual peaks. When the gaging stations in the sample for regression analysis have widely varying record lengths and concurrent peak flows, which are correlated between sites, the generalizedleast-squares procedure provides more accurate estimates of the regression coefficients and model error than does the ordinary-least-squares procedure. These flood-frequency equations provide managers with improved tools for estimating flood frequencies for purposes of management and design.

@misc{doi103133wri914037,
    author = "Landers, Mark N. and Wilson, K.V.",
    title = "Flood characteristics of Mississippi streams",
    year = "1991",
    abstract = "Flood magnitudes for selected recurrence intervals from 2 to 500 years were determined for 330 gaged sites in the study area where annual peak-flow records have been collected. The principal study area is Mississippi; however, selected data collected in adjoining States on streams draining into or from Mississippi are also included, flood frequency at a gaged stream site is defined by fitting the Pearson Type III probability distribution to the log-transformed annual peaks. The accuracy of the flood frequency determined for a gaged site is determined primarily by the number of years of annual peak-flow record (the sample size). Greater accuracy is achieved in the current analysis than in previous analyses because of the additional years of annual peak-flow record. Flood-frequency and basin characteristics at gaged sites were used to develop regression equations for estimating flood frequency where annual peak-flow records are not available.Flood frequency for ungaged stream sites in Mississippi may be estimated using basin characteristics in regression equations. Regression equations were computed using the generalized-least-squares procedure rather than the ordinary-least-squares procedure used in previous regional hydrologic analyses. The generalized-least-squares procedure considers the variable error of the gaging station flood frequencies and corrects for the cross-correlation of concurrent annual peaks. When the gaging stations in the sample for regression analysis have widely varying record lengths and concurrent peak flows, which are correlated between sites, the generalizedleast-squares procedure provides more accurate estimates of the regression coefficients and model error than does the ordinary-least-squares procedure. These flood-frequency equations provide managers with improved tools for estimating flood frequencies for purposes of management and design.",
    url = "https://doi.org/10.3133/wri914037",
    doi = "10.3133/wri914037",
    openalex = "W2111148060",
    references = "crossref1985floodflow, doi10100797894009395309, doi101029wr010i002p00211, doi101029wr021i009p01421, doi101029wr022i010p01487, doi101098rspa19300185, doi101111j175216881981tb03932x, doi10313325250, doi103133wsp1681, doi103133wsp1975, doi103133wsp2207"
}

Widespread flooding occurred in December 1982 and in spring 1983 in the central and southern Mississippi River basin. The first series of storms, December 2-7, caused severe flooding along many streams in Illinois, Missouri, and Arkansas. Much of the three-State area experienced recordbreaking 24-hour rainfall amounts that caused some streams to exceed previously known flood heights and discharges; in many cases the recurrence interval of peak discharges exceeded 100 years. The second series of storms, December 24-29, caused severe flooding in Louisiana and moderate flooding in Mississippi. Peak discharges on some streams exceeded the 100-year recurrence interval. Damages exceeded $200 million and 25 persons died as a result of the December storms. Western Tennessee was on the fringes of both storms and received only minor flooding. During April 4-8, 1983, as much as 17 inches of rain fell in parts of southern Mississippi and southeastern Louisiana. In some areas, 24-hour amounts exceeded 5 inches, causing peak discharges to exceed the recurrence interval of 100 years at 20 streamflow gaging stations. In May 1983 heavy and intense rains caused major flooding in the Big Black River and Pearl River basins in Mississippi.

@misc{doi103133wsp2362,
    author = "Stone, Roy and Bingham, Roy H.",
    title = "Floods of December 1982 to May 1983 in the central and southern Mississippi River and the Gulf of Mexico basins",
    year = "1991",
    abstract = "Widespread flooding occurred in December 1982 and in spring 1983 in the central and southern Mississippi River basin. The first series of storms, December 2-7, caused severe flooding along many streams in Illinois, Missouri, and Arkansas. Much of the three-State area experienced recordbreaking 24-hour rainfall amounts that caused some streams to exceed previously known flood heights and discharges; in many cases the recurrence interval of peak discharges exceeded 100 years. The second series of storms, December 24-29, caused severe flooding in Louisiana and moderate flooding in Mississippi. Peak discharges on some streams exceeded the 100-year recurrence interval. Damages exceeded $200 million and 25 persons died as a result of the December storms. Western Tennessee was on the fringes of both storms and received only minor flooding. During April 4-8, 1983, as much as 17 inches of rain fell in parts of southern Mississippi and southeastern Louisiana. In some areas, 24-hour amounts exceeded 5 inches, causing peak discharges to exceed the recurrence interval of 100 years at 20 streamflow gaging stations. In May 1983 heavy and intense rains caused major flooding in the Big Black River and Pearl River basins in Mississippi.",
    url = "https://doi.org/10.3133/wsp2362",
    doi = "10.3133/wsp2362",
    openalex = "W83999214",
    references = "doi10313325250"
}

@article{doi103133ofr9275,
    author = "Slack, Larry J. and Oakley, W.T.",
    title = "Tritium analyses of water in the Mississippi River alluvial aquifer in northwestern Mississippi, August 1991",
    year = "1992",
    journal = "Antarctica A Keystone in a Changing World",
    url = "https://doi.org/10.3133/ofr9275",
    doi = "10.3133/ofr9275",
    openalex = "W366749520",
    references = "doi103133wsp2292"
}

Significant water-level declines in the Mississippi River Valley alluvial aquifer prompted the need to better understand the flow system in the aquifer which, in turn, led to the development of digital groundwater flow models of the alluvial aquifer. Two models were developed in the eastern Arkansas study area with the Arkansas River dividing the study area and functioning as a hydrologic boundary to the models. Both models simulate groundwater flow in one layer with recharge entering the aquifer from head-dependent surface infiltration through the overlying confining unit and from seepage through river beds. Digital models were used to simulate flow in the aquifer during seven stress periods between 1918 and 1987. Pumpage used in the simulations ranged from 83,400,000 to 412,000,000 cu ft/d in the north model and from 12,800,000 to 58,500,000 cu ft/d in the south model. Three different spatial and temporal pumpage scenarios were tested to simulate pumpage stress in the models. The pumpage distribution used in the calibrated model was based on a combination of all three scenarios. Several criteria were used during model development to determine how well the model simulated conditions in the aquifer. Potentiometric maps of model-computed water levels were compared to measured data to check the computed water levels and direction of flow. Hydrographs of observation wells were compared to computed water levels at corresponding model cells to assess the temporal distribution of pumpage. A root-mean-square error analysis was performed during calibration by comparing observation-well and model-computed water levels for 1972. Sensitivity analyses were performed to determine the effects of changes in input parameters on computed heads (water levels). Both models were sensitive to changes in recharge and pumpage but the south model generally was less sensitive than the north model.

@misc{doi103133wri924106,
    author = "Mahon, Gary L. and Poynter, David T.",
    title = "Development, calibration, and testing of ground-water flow models for the Mississippi River Valley alluvial aquifer in eastern Arkansas using one-square-mile cells",
    year = "1993",
    abstract = "Significant water-level declines in the Mississippi River Valley alluvial aquifer prompted the need to better understand the flow system in the aquifer which, in turn, led to the development of digital groundwater flow models of the alluvial aquifer. Two models were developed in the eastern Arkansas study area with the Arkansas River dividing the study area and functioning as a hydrologic boundary to the models. Both models simulate groundwater flow in one layer with recharge entering the aquifer from head-dependent surface infiltration through the overlying confining unit and from seepage through river beds. Digital models were used to simulate flow in the aquifer during seven stress periods between 1918 and 1987. Pumpage used in the simulations ranged from 83,400,000 to 412,000,000 cu ft/d in the north model and from 12,800,000 to 58,500,000 cu ft/d in the south model. Three different spatial and temporal pumpage scenarios were tested to simulate pumpage stress in the models. The pumpage distribution used in the calibrated model was based on a combination of all three scenarios. Several criteria were used during model development to determine how well the model simulated conditions in the aquifer. Potentiometric maps of model-computed water levels were compared to measured data to check the computed water levels and direction of flow. Hydrographs of observation wells were compared to computed water levels at corresponding model cells to assess the temporal distribution of pumpage. A root-mean-square error analysis was performed during calibration by comparing observation-well and model-computed water levels for 1972. Sensitivity analyses were performed to determine the effects of changes in input parameters on computed heads (water levels). Both models were sensitive to changes in recharge and pumpage but the south model generally was less sensitive than the north model.",
    url = "https://doi.org/10.3133/wri924106",
    doi = "10.3133/wri924106",
    openalex = "W40583255",
    references = "doi103133wri844343"
}

The fluvial system is a major concern in modeling landform evolution in response to tectonic deformation. Three stream bed types (bedrock, coarse‐bed alluvial, and fine‐bed alluvial) differ in factors controlling their occurrence and evolution and in appropriate modeling approaches. Spatial and temporal transitions among bed types occur in response to changes in sediment characteristics and tectonic deformation. Erosion in bedrock channels depends upon the ability to scour or pluck bed material; this detachment capacity is often a power function of drainage area and gradient. Exposure of bedrock in channel beds, due to rapid downcutting or resistant rock, slows the response of headwater catchments to downstream baselevel changes. Sediment routing through alluvial channels must account for supply from slope erosion, transport rates, abrasion, and sorting. In regional landform modeling, implicit rate laws must be developed for sediment production from erosion of sub‐grid‐scale slopes and small channels.

@article{doi10102994jb00744,
    author = "Howard, A. D. and Dietrich, W. E. and Seidl, Michele A.",
    title = "Modeling fluvial erosion on regional to continental scales",
    year = "1994",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "The fluvial system is a major concern in modeling landform evolution in response to tectonic deformation. Three stream bed types (bedrock, coarse‐bed alluvial, and fine‐bed alluvial) differ in factors controlling their occurrence and evolution and in appropriate modeling approaches. Spatial and temporal transitions among bed types occur in response to changes in sediment characteristics and tectonic deformation. Erosion in bedrock channels depends upon the ability to scour or pluck bed material; this detachment capacity is often a power function of drainage area and gradient. Exposure of bedrock in channel beds, due to rapid downcutting or resistant rock, slows the response of headwater catchments to downstream baselevel changes. Sediment routing through alluvial channels must account for supply from slope erosion, transport rates, abrasion, and sorting. In regional landform modeling, implicit rate laws must be developed for sediment production from erosion of sub‐grid‐scale slopes and small channels.",
    url = "https://doi.org/10.1029/94jb00744",
    doi = "10.1029/94jb00744",
    openalex = "W2140403093",
    references = "doi101086628592"
}

ABSTRACT Contrary to common contemporary usage, alluvial fans are a naturally unique phenomenon readily distinguishable from other sedimentary environments, including gravel-bed rivers, on the basis of morphology, hydraulic processes, sedimentologic processes, and facies assemblages. The piedmont setting of alluvial fans where the feeder channel of an upland drainage basin intersects the mountain front assures that catastrophic fluid gravity flows and sediment gravity flows, including sheetfloods, rock falls, rock slides, rock avalanches, and debris flows, are major constructional processes, regardless of climate. The unconfinement of these flows at the mountain front gives rise to the high-sloping, semiconical form that typifies fans. The plano-convex cross-profile geometry inherent in this f rm is the inverse of the troughlike cross-sectional form of river systems, and precludes the development of floodplains that characterize rivers. The relatively high slope of alluvial fans creates unique hydraulic conditions where passing fluid gravity flows attain high capacity, high competency, and upper flow regime, resulting in sheetfloods that deposit low-angle antidune or surface-parallel planar-stratified sequences. These waterlaid facies contrast with the typically lower-flow-regime thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences, of rivers. The unconfinement of flows on fans causes a swift decrease in velocity, competency, and capacity as they attenuate, inducing rapid deposition that leads to the angular, poorly sorted textures and short radii typical of fans. This condition is markedly different than for rivers, where sediment gravity flows are rare and water flows remain confined by channel walls or spill into floodplains, and increase in depth downstream. The distinctive processes that construct alluvial fans, coupled with the secondary surficial reworking of their deposits, yield unique facies assemblages that permit the easy differentiation of fan sequences even where the geomorphic context has been lost, including in the rock record. The fault-proximal piedmont setting critical for their preservation makes properly identified alluvial-fan deposits in the rock record an invaluable tool for reconstructing and interpreting the tectonic and stratigraphic evolution of ancient sedimentary basins and their contained register of Earth history.

@article{doi101306d4267dde2b2611d78648000102c1865d,
    author = "Blair, John G. McPhe Terence C.",
    title = "Alluvial Fans and their Natural Distinction from Rivers Based on Morphology, Hydraulic Processes, Sedimentary Processes, and Facies Assemblages",
    year = "1994",
    journal = "Journal of Sedimentary Research",
    abstract = "ABSTRACT Contrary to common contemporary usage, alluvial fans are a naturally unique phenomenon readily distinguishable from other sedimentary environments, including gravel-bed rivers, on the basis of morphology, hydraulic processes, sedimentologic processes, and facies assemblages. The piedmont setting of alluvial fans where the feeder channel of an upland drainage basin intersects the mountain front assures that catastrophic fluid gravity flows and sediment gravity flows, including sheetfloods, rock falls, rock slides, rock avalanches, and debris flows, are major constructional processes, regardless of climate. The unconfinement of these flows at the mountain front gives rise to the high-sloping, semiconical form that typifies fans. The plano-convex cross-profile geometry inherent in this f rm is the inverse of the troughlike cross-sectional form of river systems, and precludes the development of floodplains that characterize rivers. The relatively high slope of alluvial fans creates unique hydraulic conditions where passing fluid gravity flows attain high capacity, high competency, and upper flow regime, resulting in sheetfloods that deposit low-angle antidune or surface-parallel planar-stratified sequences. These waterlaid facies contrast with the typically lower-flow-regime thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences, of rivers. The unconfinement of flows on fans causes a swift decrease in velocity, competency, and capacity as they attenuate, inducing rapid deposition that leads to the angular, poorly sorted textures and short radii typical of fans. This condition is markedly different than for rivers, where sediment gravity flows are rare and water flows remain confined by channel walls or spill into floodplains, and increase in depth downstream. The distinctive processes that construct alluvial fans, coupled with the secondary surficial reworking of their deposits, yield unique facies assemblages that permit the easy differentiation of fan sequences even where the geomorphic context has been lost, including in the rock record. The fault-proximal piedmont setting critical for their preservation makes properly identified alluvial-fan deposits in the rock record an invaluable tool for reconstructing and interpreting the tectonic and stratigraphic evolution of ancient sedimentary basins and their contained register of Earth history.",
    url = "https://doi.org/10.1306/d4267dde-2b26-11d7-8648000102c1865d",
    doi = "10.1306/d4267dde-2b26-11d7-8648000102c1865d",
    openalex = "W2156154267"
}

Skuna River at State Highway 9 at Bruce, Calhoun County, Mississippi, has geomorphically responded to channel modifications by lowering of the channel bed through degradation, which heightened and steepened channel banks and induced widening. Skuna River Canal (Skuna River) has typically degraded about 16.5 feet and widened about 150 feet from 1925 (when constructed) to 1992. Old Skuna River has degraded and widened about 11 feet and 40 feet, respectively, from 1921 to 1991. Skuna River Canal tributary has degraded about 6 feet from 1921 to 1991. Most of the geomorphic response on the Old River and the tributary seems to be a consequence of modifications of the canal. The bankfull discharge of the canal has increased about 1,450 percent, and the channel slope has decreased about 34 percent from 1925 to 1989. The bankfull stream power has been decreasing since 1980. The bankfull channel width-depth ratio has been increasing since 1975, which indicates the canal has been widening more than degrading since 1975. As much as 1 foot of additional degradation and 40 feet of additional widening are projected through 2010 on Skuna River Canal in the vicinity of State Highway 9. About 70 feet of additional widening could occur before the canal reaches quasi-equilibrium, which will likely be reached after 2010. If Old Skuna River and Skuna River Canal tributary degrade as much as the canal, which is doubtful, then about 6 and 11 feet of additional degradation could occur by 2010 on the Old Skuna River and the tributary, respectively, at State Highway 9. Old Skuna River and the tributary could both widen an additional 30 feet in the next 10 to 20 years. The channel low-stage thalweg of Skuna River Canal is beginning to meander around sandbars inducing lateral erosion of the channel banks. The widening projections in this report do not directly account for lateral erosion and are considered to be a minimum for the typical channel reach. Lateral erosion will likely have a significant effect on future widening site.

@misc{doi103133wri944000,
    author = "Wilson, K.V. and Turnipseed, D. Phil",
    title = "Geomorphic response to channel modifications of Skuna River at the State Highway 9 crossing at Bruce, Calhoun County, Mississippi",
    year = "1994",
    abstract = "Skuna River at State Highway 9 at Bruce, Calhoun County, Mississippi, has geomorphically responded to channel modifications by lowering of the channel bed through degradation, which heightened and steepened channel banks and induced widening. Skuna River Canal (Skuna River) has typically degraded about 16.5 feet and widened about 150 feet from 1925 (when constructed) to 1992. Old Skuna River has degraded and widened about 11 feet and 40 feet, respectively, from 1921 to 1991. Skuna River Canal tributary has degraded about 6 feet from 1921 to 1991. Most of the geomorphic response on the Old River and the tributary seems to be a consequence of modifications of the canal. The bankfull discharge of the canal has increased about 1,450 percent, and the channel slope has decreased about 34 percent from 1925 to 1989. The bankfull stream power has been decreasing since 1980. The bankfull channel width-depth ratio has been increasing since 1975, which indicates the canal has been widening more than degrading since 1975. As much as 1 foot of additional degradation and 40 feet of additional widening are projected through 2010 on Skuna River Canal in the vicinity of State Highway 9. About 70 feet of additional widening could occur before the canal reaches quasi-equilibrium, which will likely be reached after 2010. If Old Skuna River and Skuna River Canal tributary degrade as much as the canal, which is doubtful, then about 6 and 11 feet of additional degradation could occur by 2010 on the Old Skuna River and the tributary, respectively, at State Highway 9. Old Skuna River and the tributary could both widen an additional 30 feet in the next 10 to 20 years. The channel low-stage thalweg of Skuna River Canal is beginning to meander around sandbars inducing lateral erosion of the channel banks. The widening projections in this report do not directly account for lateral erosion and are considered to be a minimum for the typical channel reach. Lateral erosion will likely have a significant effect on future widening site.",
    url = "https://doi.org/10.3133/wri944000",
    doi = "10.3133/wri944000",
    openalex = "W2182524728",
    references = "doi103133wri914037"
}

Natural and human disturbances have had fundamentally different effects on ecosystems. Range scientists have proposed a new successional model, a "state-and-transition model,"which recognizes the possibility of multiple stable states in vegetation. This paper assesses this model via an investigation of the influence of fluvial processes and landforms on variation in a mosaic of riparian vegetation patches of different ages on a river reach in montane southwestern Colorado. We sampled the composition of herbaceous and shrubby plants in 67 contiguous patches along a 6 km reach of the river, measured 14 environmental variables in each patch, and then analyzed the relationship of the vegetation and environmental gradients using correspondence analysis. The variation in vegetation correlates most higly with the age of the patch, surficial-sediment size, and soil development, which represent different aspects of a gradient in time since last disturbance by floods. A consistent pattern of post-flood succession is not evident in the trends in species richness, mean percent cover, and species composition. The evidence suggests that exceptional floods in 1911 and 1927 altered fundamentally the physical environment on newly exposed bars. As a result, succession slowed and its trajectory may have been redirected toward a new stable state. While this may be a case of multiple stable states in a natural ecosystem, we suggest that such cases are rare in natural ecosystems. We also argue that proponents of state-and-transition models conclude wrongly that these models imply that managers can, or should, choose the desired state based primarily on human uses instead of managing for the potential natural vegetation. That decision is a societal one that should not be implicit in a successional model.

@article{doi101111j146783061995tb01797x,
    author = "Baker, William L. and Walford, Gillian M.",
    title = "Multiple Stable States and Models of Riparian Vegetation Succession on the Animas River, Colorado",
    year = "1995",
    journal = "Annals of the Association of American Geographers",
    abstract = {Natural and human disturbances have had fundamentally different effects on ecosystems. Range scientists have proposed a new successional model, a "state-and-transition model,"which recognizes the possibility of multiple stable states in vegetation. This paper assesses this model via an investigation of the influence of fluvial processes and landforms on variation in a mosaic of riparian vegetation patches of different ages on a river reach in montane southwestern Colorado. We sampled the composition of herbaceous and shrubby plants in 67 contiguous patches along a 6 km reach of the river, measured 14 environmental variables in each patch, and then analyzed the relationship of the vegetation and environmental gradients using correspondence analysis. The variation in vegetation correlates most higly with the age of the patch, surficial-sediment size, and soil development, which represent different aspects of a gradient in time since last disturbance by floods. A consistent pattern of post-flood succession is not evident in the trends in species richness, mean percent cover, and species composition. The evidence suggests that exceptional floods in 1911 and 1927 altered fundamentally the physical environment on newly exposed bars. As a result, succession slowed and its trajectory may have been redirected toward a new stable state. While this may be a case of multiple stable states in a natural ecosystem, we suggest that such cases are rare in natural ecosystems. We also argue that proponents of state-and-transition models conclude wrongly that these models imply that managers can, or should, choose the desired state based primarily on human uses instead of managing for the potential natural vegetation. That decision is a societal one that should not be implicit in a successional model.},
    url = "https://doi.org/10.1111/j.1467-8306.1995.tb01797.x",
    doi = "10.1111/j.1467-8306.1995.tb01797.x",
    openalex = "W1915115280",
    references = "doi101029tr035i006p00951, doi103133wsp1677"
}

@article{doi101016s0013795296000117,
    author = "Smith, Lawson M.",
    title = "Fluvial geomorphic features of the Lower Mississippi alluvial valley",
    year = "1996",
    journal = "Engineering Geology",
    url = "https://www.semanticscholar.org/paper/275e553f7d9ef4cc985b667a892442d5598546ae",
    doi = "10.1016/S0013-7952(96)00011-7",
    is_oa = "true",
    number = "1-4",
    pages = "139-165",
    semanticscholar_citation_count = "26",
    semanticscholar_id = "275e553f7d9ef4cc985b667a892442d5598546ae",
    volume = "45"
}

@article{doi1023071352458,
    author = "Rabalais, Nancy N. and Turner, R. Eugene and Justić, Dubravko and Dortch, Quay and Wiseman, William J. and Gupta, Barun K. Sen and Justić, Dubravko",
    title = "Nutrient Changes in the Mississippi River and System Responses on the Adjacent Continental Shelf",
    year = "1996",
    journal = "Estuaries",
    url = "https://doi.org/10.2307/1352458",
    doi = "10.2307/1352458",
    openalex = "W1979102125",
    references = "doi101038368619a0, doi101086628741, doi101111j174973451990tb00529x, doi101126science223463122, doi102216i00318884322791, doi1023071311453, doi1023072992511, doi102475ajs2824401, doi104319lo1988334part20796, openalexw3146967818"
}

@article{smith1996fluvial,
    author = "Smith, Lawson M.",
    title = "Fluvial geomorphic features of the Lower Mississippi alluvial valley",
    year = "1996",
    journal = "Engineering Geology",
    url = "https://doi.org/10.1016/s0013-7952(96)00011-7",
    doi = "10.1016/s0013-7952(96)00011-7",
    number = "1-4",
    openalex = "W2093973445",
    pages = "139-165",
    volume = "45",
    references = "doi101086625561, doi1011300016760619931050521aotsoo23co2, doi101130dnaggnak2, doi101130dnaggnak2547, doi101306212f90ca2b2411d78648000102c1865d, doi102307211375, openalexw1537229464, openalexw1602720119, openalexw596100700, openalexw814649432"
}

The Great Flood of 1993 was one of the costliest natural disasters in American history. This flood was primarily the result of a persistent weather pattern that delivered precipitation across a very large part of the Midwest for an extended period of the summer. In contrast to normal years when most places in the region receive about half of their annual precipitation between May and August, many places received the equivalent of the annual rainfall in that time period in 1993. Much of this rain fell on soils that were already saturated and unable to store additional runoff. Annual and monthly rainfall totals for the states of Iowa, Minnesota, and Illinois for 1993 were the highest in 100 years. Precipitation was highest in Iowa, where the annual total precipitation of 1,200 mm was estimated to have an exceedence probability of 0.001. Peak discharges on the upper Mississippi and lower Missouri Rivers were likewise characterized by low probabilities, but these estimates can be interpreted very differently depending on the assumptions used in the analysis. In contrast to the main-stem rivers, flooding on tributary streams, whether expressed in terms of return period or discharge per unit drainage area, was less extreme. Arguments put forth in the popular press and elsewhere that land-use modifications in the Mississippi River basin exacerbated flooding in 1993 are reviewed in detail, and it is suggested that these effects may be important for floods with return periods < 50 years but have much less influence on floods of this magnitude.

@article{doi1011110004560800044,
    author = "Pitlick, John",
    title = "A Regional Perspective of the Hydrology of the 1993 Mississippi River Basin Floods",
    year = "1997",
    journal = "Annals of the Association of American Geographers",
    abstract = "The Great Flood of 1993 was one of the costliest natural disasters in American history. This flood was primarily the result of a persistent weather pattern that delivered precipitation across a very large part of the Midwest for an extended period of the summer. In contrast to normal years when most places in the region receive about half of their annual precipitation between May and August, many places received the equivalent of the annual rainfall in that time period in 1993. Much of this rain fell on soils that were already saturated and unable to store additional runoff. Annual and monthly rainfall totals for the states of Iowa, Minnesota, and Illinois for 1993 were the highest in 100 years. Precipitation was highest in Iowa, where the annual total precipitation of 1,200 mm was estimated to have an exceedence probability of 0.001. Peak discharges on the upper Mississippi and lower Missouri Rivers were likewise characterized by low probabilities, but these estimates can be interpreted very differently depending on the assumptions used in the analysis. In contrast to the main-stem rivers, flooding on tributary streams, whether expressed in terms of return period or discharge per unit drainage area, was less extreme. Arguments put forth in the popular press and elsewhere that land-use modifications in the Mississippi River basin exacerbated flooding in 1993 are reviewed in detail, and it is suggested that these effects may be important for floods with return periods < 50 years but have much less influence on floods of this magnitude.",
    url = "https://doi.org/10.1111/0004-5608.00044",
    doi = "10.1111/0004-5608.00044",
    openalex = "W2050540835",
    references = "doi103133wsp1677, openalexw244848745"
}

The States of Arkansas, Louisiana, and Mississippi, which are located adjacent to each other and north of the Gulf of Mexico, compose Segment 5 of this Atlas. The three-State area encompasses an area of nearly 149,000 square miles. These States are drained by numerous rivers and streams, such as the Atchafalaya, the Teche, the Vermilion, the Calcasieu, the Mermentau, the Sabine, the Tombigbee, the Pascagoula, the Wolf, and the Pearl Rivers, that drain directly to the Gulf of Mexico. The Yazoo, the Big Black, the Arkansas, the St. Francis, the Red, and the White Rivers are tributaries of the Mississippi River, which is the largest of the rivers that drain the three States. Although surface water is the largest source of freshwater to public supply, domestic and commercial, industrial, mining, thermoelectric power and agricultural users, ground water also is important and accounts for 38 percent of total water use in Arkansas, Louisiana, and Mississippi. Precipitation is the ultimate source of water that recharges the ma-jor aquifers in Segment 5. Average annual rainfall (1951-80) amounts range from about 40 to about 68 inches (fig. 1). Temporal (seasonal) and spatial variations in precipitation are evident in the three-State area. Average annual rainfall is greatest (60 inches per year or more) in southern Louisiana and southern Mississippi and diminishes in Arkansas and in northwestern Louisiana. Precipitation is greatest during January and May in Arkansas. May to September represent the wettest months in southeastern Louisiana and southern Mississippi. March and April are the wettest months in northern Mississippi. Average annual (1951-80) runoff ranges from less than 12 inches in western Louisiana and northwestern Arkansas to more than 20 inches in southern and northern Mississippi and in central and western Arkansas (fig. 2). Comparison of precipitation and runoff maps shows that less than one-half of the annual precipitation leaves the area as stream runoff. Much of the water that does not exit Segment 5 as runoff is returned to the atmosphere by evapotranspiration, which is the combination of transpiration by vegetation and evaporation from marshes, swamps, lakes and streams. A small amount of water recharges aquifers that are either exposed or buried to shallow depths, and an even smaller amount percolates downward and enters the deep flow system.

@misc{doi103133ha730f,
    author = "Renken, Robert A.",
    title = "Ground Water Atlas of the United States: Segment 5, Arkansas, Louisiana, Mississippi",
    year = "1998",
    abstract = "The States of Arkansas, Louisiana, and Mississippi, which are located adjacent to each other and north of the Gulf of Mexico, compose Segment 5 of this Atlas. The three-State area encompasses an area of nearly 149,000 square miles. These States are drained by numerous rivers and streams, such as the Atchafalaya, the Teche, the Vermilion, the Calcasieu, the Mermentau, the Sabine, the Tombigbee, the Pascagoula, the Wolf, and the Pearl Rivers, that drain directly to the Gulf of Mexico. The Yazoo, the Big Black, the Arkansas, the St. Francis, the Red, and the White Rivers are tributaries of the Mississippi River, which is the largest of the rivers that drain the three States. Although surface water is the largest source of freshwater to public supply, domestic and commercial, industrial, mining, thermoelectric power and agricultural users, ground water also is important and accounts for 38 percent of total water use in Arkansas, Louisiana, and Mississippi. Precipitation is the ultimate source of water that recharges the ma-jor aquifers in Segment 5. Average annual rainfall (1951-80) amounts range from about 40 to about 68 inches (fig. 1). Temporal (seasonal) and spatial variations in precipitation are evident in the three-State area. Average annual rainfall is greatest (60 inches per year or more) in southern Louisiana and southern Mississippi and diminishes in Arkansas and in northwestern Louisiana. Precipitation is greatest during January and May in Arkansas. May to September represent the wettest months in southeastern Louisiana and southern Mississippi. March and April are the wettest months in northern Mississippi. Average annual (1951-80) runoff ranges from less than 12 inches in western Louisiana and northwestern Arkansas to more than 20 inches in southern and northern Mississippi and in central and western Arkansas (fig. 2). Comparison of precipitation and runoff maps shows that less than one-half of the annual precipitation leaves the area as stream runoff. Much of the water that does not exit Segment 5 as runoff is returned to the atmosphere by evapotranspiration, which is the combination of transpiration by vegetation and evaporation from marshes, swamps, lakes and streams. A small amount of water recharges aquifers that are either exposed or buried to shallow depths, and an even smaller amount percolates downward and enters the deep flow system.",
    url = "https://doi.org/10.3133/ha730f",
    doi = "10.3133/ha730f",
    openalex = "W118405612",
    references = "crossref1978the, doi1010160022169464900198, doi101029wr021i010p01545, doi101111j136530911965tb01561x, doi10113000167606197283575gahotg20co2, doi101130dnaggnao2165, doi101130dnaggnao2219, doi101306d42695bc2b2611d78648000102c1865d, doi1023071788077, openalexw2097985193, openalexw657807096"
}

Over the last century, the river-dominated Mississippi delta has received increasing attention from geoscientists, biologists, engineers, and environmental planners because of the importance of the river and its deltaic environments to the economic well-being of the state of Louisiana and the nation. Population growth, subsurface resource extraction, and increased land-water use have placed demands on the delta's natural geologic, biologic, and chemical systems, therefore modifying the time and spatial scales of natural processes within the delta and its lower alluvial valley. As a result, the combined effects of natural and human-induced processes, such as subsidence, eustatic sea level rise, salt water intrusion, and wetland loss, have produced a dynamically changing landscape and socioeconomic framework for this complex delta. Under natural conditions, the fundamental changes that result in land-building and land loss in the Holocene Mississippi River delta plain are rooted in the systematic diversion of water and sediment associated with major shifts in the river's course-the process of delta switching. Research over the last half century has shown that major relocations of the Mississippi's course have resulted in five Holocene delta complexes and a sixth one in an early stage of development as a product of the latest Atchafalaya River diversion. Collectively, these Holocene deltas have produced a delta plain that covers an area of ~30,000 km and accounts for 41% of the coastal wetlands in the United States. After a river diversion takes place, the resulting delta evolves through a systematic and semipredictable set of stages generally characterized by: (a) rapid progradation with increasing-to-stable discharge, (b) relative stability during initial stages of waning discharge, (c) abandonment by the river in favor of a higher gradient course to the receiving basin, and (d) marine reworking of a sediment-starved delta as it undergoes progressive submergence by the combined processes of subsidence. Delta switching has taken place every 1000 to 2000 years during Holocene times, and resulting deltas have an average thickness of approximately 35 m. Within a single delta there are subdeltas, bayfills, and crevasse-splays that have higher frequency delta cycles ranging from several hundred years to a few decades. These depositional features are usually less than 10 m thick, and some have produced marshland areas of over 300 km. The net result of these delta-building events is a low-lying landscape with components that are changing (building and deteriorating) at different rates. Geologically, these depositional cycles produce a thick accumulation of coarsening, upward deltaic deposits that have various thicknesses in response to development on a variety of temporal and spatial scales. In this river-dominated delta system, distributaries can prograde seaward at rates of over 100 m/year. The cumulative effect of the Holocene depository has been to depress the underlying Pleistocene surface. In a local setting, e.g., the modern Balize Lobe, differential loading causes the vertical displacement of underlying clay-rich facies (shale diapirs-mudlumps). The delta front of this lobe, which has prograded into deep water of the outer continental shelf, is characterized by rapid deposition of silt- and clay-rich sediments and slope instability, which results in seaward displacement of sediments by a variety of mass-movement processes. Superimposed on the natural processes and forms of the Mississippi deltaic plain and its associated estuarine environments, are human impacts, most of which have been imposed in this century. The most significant impacts have resulted from a decrease in sediment input to the river from its tributaries and the alteration of the river's natural sediment dispersal processes through the construction of levees. Measures are now being taken to reinstate some of the delta's natural processes, thereby mitigating landloss so that decline in animal and plant productivity can be mitigated. 2 2

@article{openalexw1846023905,
    author = "Coleman, James M. and Roberts, Harry H. and Stone, Gregory W.",
    title = "Mississippi River Delta: an Overview",
    year = "1998",
    journal = "Civil War Book Review",
    abstract = "Over the last century, the river-dominated Mississippi delta has received increasing attention from geoscientists, biologists, engineers, and environmental planners because of the importance of the river and its deltaic environments to the economic well-being of the state of Louisiana and the nation. Population growth, subsurface resource extraction, and increased land-water use have placed demands on the delta's natural geologic, biologic, and chemical systems, therefore modifying the time and spatial scales of natural processes within the delta and its lower alluvial valley. As a result, the combined effects of natural and human-induced processes, such as subsidence, eustatic sea level rise, salt water intrusion, and wetland loss, have produced a dynamically changing landscape and socioeconomic framework for this complex delta. Under natural conditions, the fundamental changes that result in land-building and land loss in the Holocene Mississippi River delta plain are rooted in the systematic diversion of water and sediment associated with major shifts in the river's course-the process of delta switching. Research over the last half century has shown that major relocations of the Mississippi's course have resulted in five Holocene delta complexes and a sixth one in an early stage of development as a product of the latest Atchafalaya River diversion. Collectively, these Holocene deltas have produced a delta plain that covers an area of \textasciitilde 30,000 km and accounts for 41\% of the coastal wetlands in the United States. After a river diversion takes place, the resulting delta evolves through a systematic and semipredictable set of stages generally characterized by: (a) rapid progradation with increasing-to-stable discharge, (b) relative stability during initial stages of waning discharge, (c) abandonment by the river in favor of a higher gradient course to the receiving basin, and (d) marine reworking of a sediment-starved delta as it undergoes progressive submergence by the combined processes of subsidence. Delta switching has taken place every 1000 to 2000 years during Holocene times, and resulting deltas have an average thickness of approximately 35 m. Within a single delta there are subdeltas, bayfills, and crevasse-splays that have higher frequency delta cycles ranging from several hundred years to a few decades. These depositional features are usually less than 10 m thick, and some have produced marshland areas of over 300 km. The net result of these delta-building events is a low-lying landscape with components that are changing (building and deteriorating) at different rates. Geologically, these depositional cycles produce a thick accumulation of coarsening, upward deltaic deposits that have various thicknesses in response to development on a variety of temporal and spatial scales. In this river-dominated delta system, distributaries can prograde seaward at rates of over 100 m/year. The cumulative effect of the Holocene depository has been to depress the underlying Pleistocene surface. In a local setting, e.g., the modern Balize Lobe, differential loading causes the vertical displacement of underlying clay-rich facies (shale diapirs-mudlumps). The delta front of this lobe, which has prograded into deep water of the outer continental shelf, is characterized by rapid deposition of silt- and clay-rich sediments and slope instability, which results in seaward displacement of sediments by a variety of mass-movement processes. Superimposed on the natural processes and forms of the Mississippi deltaic plain and its associated estuarine environments, are human impacts, most of which have been imposed in this century. The most significant impacts have resulted from a decrease in sediment input to the river from its tributaries and the alteration of the river's natural sediment dispersal processes through the construction of levees. Measures are now being taken to reinstate some of the delta's natural processes, thereby mitigating landloss so that decline in animal and plant productivity can be mitigated. 2 2",
    url = "https://openalex.org/W1846023905",
    openalex = "W1846023905",
    references = "doi101016s0967065397885973, doi101086625561, doi101126science27352821693, doi1011300016760619881000999dcapit23co2, doi101306212f8ec22b2411d78648000102c1865d, doi101306ad461b9216f711d78645000102c1865d, doi101306sv21353, doi102307211375, doi105724gcs91120034, openalexw1592594904, openalexw2971039300"
}

The longitudinal profiles of bedrock channels are a major component of the relief structure of mountainous drainage basins and therefore limit the elevation of peaks and ridges. Further, bedrock channels communicate tectonic and climatic signals across the landscape, thus dictating, to first order, the dynamic response of mountainous landscapes to external forcings. We review and explore the stream‐power erosion model in an effort to (1) elucidate its consequences in terms of large‐scale topographic (fluvial) relief and its sensitivity to tectonic and climatic forcing, (2) derive a relationship for system response time to tectonic perturbations, (3) determine the sensitivity of model behavior to various model parameters, and (4) integrate the above to suggest useful guidelines for further study of bedrock channel systems and for future refinement of the streampower erosion law. Dimensional analysis reveals that the dynamic behavior of the stream‐power erosion model is governed by a single nondimensional group that we term the uplift‐erosion number, greatly reducing the number of variables that need to be considered in the sensitivity analysis. The degree of nonlinearity in the relationship between stream incision rate and channel gradient (slope exponent n) emerges as a fundamental unknown. The physics of the active erosion processes directly influence this nonlinearity, which is shown to dictate the relationship between the uplift‐erosion number, the equilibrium stream channel gradient, and the total fluvial relief of mountain ranges. Similarly, the predicted response time to changes in rock uplift rate is shown to depend on climate, rock strength, and the magnitude of tectonic perturbation, with the slope exponent n controlling the degree of dependence on these various factors. For typical drainage basin geometries the response time is relatively insensitive to the size of the system. Work on the physics of bedrock erosion processes, their sensitivity to extreme floods, their transient responses to sudden changes in climate or uplift rate, and the scaling of local rock erosion studies to reach‐scale modeling studies are most sorely needed.

@article{doi1010291999jb900120,
    author = "Whipple, K. X. and Tucker, Gregory E.",
    title = "Dynamics of the stream‐power river incision model: Implications for height limits of mountain ranges, landscape response timescales, and research needs",
    year = "1999",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "The longitudinal profiles of bedrock channels are a major component of the relief structure of mountainous drainage basins and therefore limit the elevation of peaks and ridges. Further, bedrock channels communicate tectonic and climatic signals across the landscape, thus dictating, to first order, the dynamic response of mountainous landscapes to external forcings. We review and explore the stream‐power erosion model in an effort to (1) elucidate its consequences in terms of large‐scale topographic (fluvial) relief and its sensitivity to tectonic and climatic forcing, (2) derive a relationship for system response time to tectonic perturbations, (3) determine the sensitivity of model behavior to various model parameters, and (4) integrate the above to suggest useful guidelines for further study of bedrock channel systems and for future refinement of the streampower erosion law. Dimensional analysis reveals that the dynamic behavior of the stream‐power erosion model is governed by a single nondimensional group that we term the uplift‐erosion number, greatly reducing the number of variables that need to be considered in the sensitivity analysis. The degree of nonlinearity in the relationship between stream incision rate and channel gradient (slope exponent n) emerges as a fundamental unknown. The physics of the active erosion processes directly influence this nonlinearity, which is shown to dictate the relationship between the uplift‐erosion number, the equilibrium stream channel gradient, and the total fluvial relief of mountain ranges. Similarly, the predicted response time to changes in rock uplift rate is shown to depend on climate, rock strength, and the magnitude of tectonic perturbation, with the slope exponent n controlling the degree of dependence on these various factors. For typical drainage basin geometries the response time is relatively insensitive to the size of the system. Work on the physics of bedrock erosion processes, their sensitivity to extreme floods, their transient responses to sudden changes in climate or uplift rate, and the scaling of local rock erosion studies to reach‐scale modeling studies are most sorely needed.",
    url = "https://doi.org/10.1029/1999jb900120",
    doi = "10.1029/1999jb900120",
    openalex = "W1993999355",
    references = "doi10102994wr00757, doi101029gm107p0297, doi102307622211"
}

ABSTRACT The alluvial architecture and soil characteristics of Holo cene Mississippi River floodplain deposits in the southern Lower Mississippi Valley provide evidence for significant changes in floodplain development in response to sea-level rise. Floodplain cores acquired near Ferriday, Louisiana show that Holocene deposits consist of 15-30 m (ave. 20 m) of sands, silts, and clays, which overlie Late Wisconsin sands and gravels. On the basis of differences in sediment grain size, sediment-body geometry, and the abundance of soil features, the Holocene deposits are subdivided into Lower and Upper Holocene units. Lower Holocene deposits (> 5000 yr B.P.) consist of lacustrine and poorly drained backswamp muds that contain authigenic siderite, pyrite, and vivianite and show little evidence of soil formation. Muds encase crevasse-splay and floodplain-channel sand bodies (< 1 km wide), and collectively these deposits represent a mosaic of shallow lakes, poorly drained backswamps, and multichannel streams, similar to modern examples in the Atchafalaya Basin (100 km south of Ferriday). Upper Holocene deposits (< 5000 yr B.P.) are represented by large Mississippi River meander-belt sand bodies that are up to 15 km wide and 30 m thick. Natural-levee silts and sands and well drained backswamp muds are present between meander-belt sands. Upper Holocene deposits contain abundant soil features, and sandy and silty soils are Entisols, Inceptisols, and Alfisols whereas clayey soils are Vertisols. The presence of isolated sand bodies surrounded by mud and the scarcity of soil features suggest that Lower Holocene sediments reflect a period of rapid floodplain aggradation during which crevassing, lacustrine sedimentation, and avulsion dominated floodplain construction. No evidence of large meandering Mississippi River channels represented by buried, thick tabular sands exists near Ferriday, and discharge in Lower Mississippi Valley flow was probably conveyed by a network of small, multichannel floodplain streams. Upper Holocene sediments record a dramatic change ca. 5000 yr B.P. from rapid to slower floodplain aggradation, which was accompanied by extensive lateral channel migration, overbank deposition, and soil formation. On the basis of differences in meander belt dimensions and numbers of abandoned channels, Upper Holocene meander belts are subdivided into simple and complex forms. Relative age relationships suggest that the smaller and older simple meander belts represent periods of divided Mississippi River flow and early attempts to establish a large, single-channel meandering regime. This type of meandering regime is represented by the larger and younger complex meander belts and includes the modern meander belt. Similarities in the timing of changes in floodplain processes and fluvial style and decreasing rates of Holocene sediment accumulation in the southern Lower Mississippi Valley strongly suggest that decelerating Holocene sea-level rise in the Gulf of Mexico affected floodplain development at least 300 km inland from the present-day coast. The alluvial architecture of the Lower Holocene deposits and the absence of large meandering Mississippi River channel deposits older than 5000 yr B.P. near Ferriday indicates that most of the floodplain muds were deposited by avulsion-related crevassing and lacustrine sedimentation rather than by overbank flooding of large Mississippi River channels. Similarities between the floodplain history of the Mississippi River and those of modern and ancient rivers elsewhere further suggest that avulsion, rather than simple overbank deposition, contributes to the construction of fine-grained floodplains to a greater degree than generally recognized.

@article{doi102110jsr69800,
    author = "Aslan, Andres and Autin, W. J.",
    title = "Evolution of the Holocene Mississippi River floodplain, Ferriday, Louisiana; insights on the origin of fine-grained floodplains",
    year = "1999",
    journal = "Journal of Sedimentary Research",
    abstract = "ABSTRACT The alluvial architecture and soil characteristics of Holo cene Mississippi River floodplain deposits in the southern Lower Mississippi Valley provide evidence for significant changes in floodplain development in response to sea-level rise. Floodplain cores acquired near Ferriday, Louisiana show that Holocene deposits consist of 15-30 m (ave. 20 m) of sands, silts, and clays, which overlie Late Wisconsin sands and gravels. On the basis of differences in sediment grain size, sediment-body geometry, and the abundance of soil features, the Holocene deposits are subdivided into Lower and Upper Holocene units. Lower Holocene deposits (> 5000 yr B.P.) consist of lacustrine and poorly drained backswamp muds that contain authigenic siderite, pyrite, and vivianite and show little evidence of soil formation. Muds encase crevasse-splay and floodplain-channel sand bodies (< 1 km wide), and collectively these deposits represent a mosaic of shallow lakes, poorly drained backswamps, and multichannel streams, similar to modern examples in the Atchafalaya Basin (100 km south of Ferriday). Upper Holocene deposits (< 5000 yr B.P.) are represented by large Mississippi River meander-belt sand bodies that are up to 15 km wide and 30 m thick. Natural-levee silts and sands and well drained backswamp muds are present between meander-belt sands. Upper Holocene deposits contain abundant soil features, and sandy and silty soils are Entisols, Inceptisols, and Alfisols whereas clayey soils are Vertisols. The presence of isolated sand bodies surrounded by mud and the scarcity of soil features suggest that Lower Holocene sediments reflect a period of rapid floodplain aggradation during which crevassing, lacustrine sedimentation, and avulsion dominated floodplain construction. No evidence of large meandering Mississippi River channels represented by buried, thick tabular sands exists near Ferriday, and discharge in Lower Mississippi Valley flow was probably conveyed by a network of small, multichannel floodplain streams. Upper Holocene sediments record a dramatic change ca. 5000 yr B.P. from rapid to slower floodplain aggradation, which was accompanied by extensive lateral channel migration, overbank deposition, and soil formation. On the basis of differences in meander belt dimensions and numbers of abandoned channels, Upper Holocene meander belts are subdivided into simple and complex forms. Relative age relationships suggest that the smaller and older simple meander belts represent periods of divided Mississippi River flow and early attempts to establish a large, single-channel meandering regime. This type of meandering regime is represented by the larger and younger complex meander belts and includes the modern meander belt. Similarities in the timing of changes in floodplain processes and fluvial style and decreasing rates of Holocene sediment accumulation in the southern Lower Mississippi Valley strongly suggest that decelerating Holocene sea-level rise in the Gulf of Mexico affected floodplain development at least 300 km inland from the present-day coast. The alluvial architecture of the Lower Holocene deposits and the absence of large meandering Mississippi River channel deposits older than 5000 yr B.P. near Ferriday indicates that most of the floodplain muds were deposited by avulsion-related crevassing and lacustrine sedimentation rather than by overbank flooding of large Mississippi River channels. Similarities between the floodplain history of the Mississippi River and those of modern and ancient rivers elsewhere further suggest that avulsion, rather than simple overbank deposition, contributes to the construction of fine-grained floodplains to a greater degree than generally recognized.",
    url = "https://doi.org/10.2110/jsr.69.800",
    doi = "10.2110/jsr.69.800",
    openalex = "W2099806028",
    references = "crossref1978the, doi1010160037073878900027, doi101016003707389390022w, doi101111j136530911965tb01561x, doi101111j136530911979tb00935x, doi101111j136530911989tb00817x, doi101306212f7c7f2b2411d78648000102c1865d, doi102110pec88010125, doi102307211375, openalexw1592594904, openalexw1973279175"
}

Summary Fluvial landforms and deposits provide one of the most readily studied Quaternary continental records, and alluvial strata represent an important component in most ancient continental interior and continental margin successions. Moreover, studies of the long‐term dynamics of fluvial systems and their responses to external or ‘allogenic' controls, can play important roles in research concerning both global change and sequence‐stratigraphy, as well as in studies of the dynamic interactions between tectonic activity and surface processes. These themes were energized in the final decades of the twentieth century, and may become increasingly important in the first decades of this millennium. This review paper provides a historical perspective on the development of ideas in the fields of geomorphology/Quaternary geology vs. sedimentary geology, and then summarizes key processes that operate to produce alluvial stratigraphic records over time‐scales of 10 3 −10 6 years. Of particular interest are changes in discharge regimes, sediment supply and sediment storage en route from source terrains to sedimentary basins, as well as changes in sea‐level and the concept of accommodation. Late Quaternary stratigraphic records from the Loire (France), Mississippi (USA), Colorado (Texas, USA) and Rhine–Meuse (The Netherlands) Rivers are used to illustrate the influences of climate change on continental interior rivers, as well as the influence of interacting climate and sea‐level change on continental margin systems. The paper concludes with a look forward to a bright future for studies of fluvial response to climate and sea‐level change. At present, empirical field‐based research on fluvial response to climate and sea‐level change lags behind: (a) the global change community's understanding of the magnitude and frequency of climate and sea‐level change; (b) the sequence‐stratigraphic community's desire to interpret climate and, especially, sea‐level change as forcing mechanisms; and (c) the modelling community's ability to generate numerical and physical models of surface processes and their stratigraphic results. A major challenge for the future is to catch up, which will require the development of more detailed and sophisticated Quaternary stratigraphic, sedimentological and geochronological frameworks in a variety of continental interior and continental margin settings. There is a particular need for studies that seek to document fluvial responses to allogenic forcing over both shorter (10 2 −10 3 years) and longer (10 4 −10 6 years) time‐scales than has commonly been the case to date, as well as in larger river systems, from source to sink. Studies of Quaternary systems in depositional basin settings are especially critical because they can provide realistic analogues for interpretation of the pre‐Quaternary rock record.

@article{doi101046j13653091200000008x,
    author = "Blum, Michael D. and Törnqvist, Torbjörn E.",
    title = "Fluvial responses to climate and sea‐level change: a review and look forward",
    year = "2000",
    journal = "Sedimentology",
    abstract = "Summary Fluvial landforms and deposits provide one of the most readily studied Quaternary continental records, and alluvial strata represent an important component in most ancient continental interior and continental margin successions. Moreover, studies of the long‐term dynamics of fluvial systems and their responses to external or ‘allogenic' controls, can play important roles in research concerning both global change and sequence‐stratigraphy, as well as in studies of the dynamic interactions between tectonic activity and surface processes. These themes were energized in the final decades of the twentieth century, and may become increasingly important in the first decades of this millennium. This review paper provides a historical perspective on the development of ideas in the fields of geomorphology/Quaternary geology vs. sedimentary geology, and then summarizes key processes that operate to produce alluvial stratigraphic records over time‐scales of 10 3 −10 6 years. Of particular interest are changes in discharge regimes, sediment supply and sediment storage en route from source terrains to sedimentary basins, as well as changes in sea‐level and the concept of accommodation. Late Quaternary stratigraphic records from the Loire (France), Mississippi (USA), Colorado (Texas, USA) and Rhine–Meuse (The Netherlands) Rivers are used to illustrate the influences of climate change on continental interior rivers, as well as the influence of interacting climate and sea‐level change on continental margin systems. The paper concludes with a look forward to a bright future for studies of fluvial response to climate and sea‐level change. At present, empirical field‐based research on fluvial response to climate and sea‐level change lags behind: (a) the global change community's understanding of the magnitude and frequency of climate and sea‐level change; (b) the sequence‐stratigraphic community's desire to interpret climate and, especially, sea‐level change as forcing mechanisms; and (c) the modelling community's ability to generate numerical and physical models of surface processes and their stratigraphic results. A major challenge for the future is to catch up, which will require the development of more detailed and sophisticated Quaternary stratigraphic, sedimentological and geochronological frameworks in a variety of continental interior and continental margin settings. There is a particular need for studies that seek to document fluvial responses to allogenic forcing over both shorter (10 2 −10 3 years) and longer (10 4 −10 6 years) time‐scales than has commonly been the case to date, as well as in larger river systems, from source to sink. Studies of Quaternary systems in depositional basin settings are especially critical because they can provide realistic analogues for interpretation of the pre‐Quaternary rock record.",
    url = "https://doi.org/10.1046/j.1365-3091.2000.00008.x",
    doi = "10.1046/j.1365-3091.2000.00008.x",
    openalex = "W2130432031",
    references = "doi1010079783662032374, doi1010160012821x96000623, doi101016001282527990059x, doi1010160012825285900017, doi1010160033589473900525, doi1010160037073878900027, doi1010160169555x9290039q, doi1010160277379187900035, doi101016s0012821x98001988, doi101017cbo9780511628948, doi10102993rg02030, doi101038324137a0, doi101038342637a0, doi101038365143a0, doi101086629606, doi101111j136530911979tb00935x, doi101111j136530911989tb00817x, doi101111j136530911993tb01347x, doi101126science19442701121, doi101126science23547931156, doi101126science2695224676, doi101126science27853411257, doi1011300016760619637493sitcio20co2, doi101130gsab28745, doi101306703c9af5170711d78645000102c1865d, doi101306m26490, doi101306mth7510, doi102110csp9907, doi102110jsr69800, doi102110pec88010039, doi102110pec88010071, doi102110pec88010109, doi102307211375, flint1947geological"
}

Abstract Many river systems in western North America retain a fluvial strath-terrace rec ord of discontinuous downcutting into bedrock through the Quaternary. Their importance lies in their use to interpret climatic events in the headwaters and to determine long-term incision rates. Terrace formation has been ascribed to changes in sediment supply and/or water discharge produced by late Quaternary climatic fluctuations. We use a one-dimensional channel- evolution model to explore whether temporal variations in sediment and water discharge can generate terrace sequences. The model includes sediment transport, vertical bedrock erosion limited by alluvial cover, and lateral valley-wall erosion. We set limits on our modeling by using data collected from the terraced Wind River basin. Two types of experiments were performed: constant- period sinusoidal input histories and variable-period inputs scaled by the marine δ18O rec ord. Our simulations indicate that strath-terrace formation requires input variability that produces a changing ratio of vertical to lateral erosion rates. Straths are cut when the channel floor is protected from erosion by sediment and are abandoned—and terraces formed—when incision can resume following sediment-cover thinning. High sediment supply promotes wide valley floors that are abandoned as sediment supply decreases. In contrast, wide valleys are promoted by low effective water discharge and are abandoned as discharge increases. Widening of the valley floors that become terraces occurs over many thousands of years. The transition from valley widening to downcutting and terrace creation occurs in response to subtle input changes affecting local divergence of sediment-transport capacity. Formation of terraces lags by several thousand years the input changes that cause their formation. Our results suggest that use of terrace ages to set limits on the timing of a specific event must be done with the knowledge that the system can take thousands of years to respond to a perturbation. The incision rate calculated in the field from the lowest terrace in these systems will likely be higher than the rate calculated by using older terraces, because the most recent fluvial response in the field is commonly downcutting associated with declining sediment input since the Last Glacial Maximum. This apparent increase in incision rates is observed in many river systems and should not necessarily be interpreted as a response to an increase in rock-uplift rate.

@article{doi1011300016760620021141131nmofst20co2,
    author = "Hancock, Gregory S. and Anderson, Robert S.",
    title = "Numerical modeling of fluvial strath-terrace formation in response to oscillating climate",
    year = "2002",
    journal = "Geological Society of America Bulletin",
    abstract = "Abstract Many river systems in western North America retain a fluvial strath-terrace rec ord of discontinuous downcutting into bedrock through the Quaternary. Their importance lies in their use to interpret climatic events in the headwaters and to determine long-term incision rates. Terrace formation has been ascribed to changes in sediment supply and/or water discharge produced by late Quaternary climatic fluctuations. We use a one-dimensional channel- evolution model to explore whether temporal variations in sediment and water discharge can generate terrace sequences. The model includes sediment transport, vertical bedrock erosion limited by alluvial cover, and lateral valley-wall erosion. We set limits on our modeling by using data collected from the terraced Wind River basin. Two types of experiments were performed: constant- period sinusoidal input histories and variable-period inputs scaled by the marine δ18O rec ord. Our simulations indicate that strath-terrace formation requires input variability that produces a changing ratio of vertical to lateral erosion rates. Straths are cut when the channel floor is protected from erosion by sediment and are abandoned—and terraces formed—when incision can resume following sediment-cover thinning. High sediment supply promotes wide valley floors that are abandoned as sediment supply decreases. In contrast, wide valleys are promoted by low effective water discharge and are abandoned as discharge increases. Widening of the valley floors that become terraces occurs over many thousands of years. The transition from valley widening to downcutting and terrace creation occurs in response to subtle input changes affecting local divergence of sediment-transport capacity. Formation of terraces lags by several thousand years the input changes that cause their formation. Our results suggest that use of terrace ages to set limits on the timing of a specific event must be done with the knowledge that the system can take thousands of years to respond to a perturbation. The incision rate calculated in the field from the lowest terrace in these systems will likely be higher than the rate calculated by using older terraces, because the most recent fluvial response in the field is commonly downcutting associated with declining sediment input since the Last Glacial Maximum. This apparent increase in incision rates is observed in many river systems and should not necessarily be interpreted as a response to an increase in rock-uplift rate.",
    url = "https://doi.org/10.1130/0016-7606(2002)114<1131:nmofst>2.0.co;2",
    doi = "10.1130/0016-7606(2002)114<1131:nmofst>2.0.co;2",
    openalex = "W2111204986"
}

publication will provide you the needed insights and information to meet your needs, and thereby foster increased awareness and involvement in the protection and restoration of our Nation's waters.The NAWQA Program recognizes that a

@misc{doi103133wri034202,
    author = "Gonthier, Gerard J.",
    title = "Quality of ground water in Pleistocene and Holocene subunits of the Mississippi River Valley alluvial aquifer, 1998",
    year = "2003",
    abstract = "publication will provide you the needed insights and information to meet your needs, and thereby foster increased awareness and involvement in the protection and restoration of our Nation's waters.The NAWQA Program recognizes that a",
    url = "https://doi.org/10.3133/wri034202",
    doi = "10.3133/wri034202",
    openalex = "W1555061828",
    references = "doi103133wri844343"
}

1. Introduction. 2. Overview of River Systems. 3. Fundamentals of Water Flow. 4. Fundamentals of Sediment Transport. 5. Bed forms and Sedimentary Structures. 6. Alluvial Channels and Bars. 7. Floodplains. 8. Along--valley Variations in Channels and Floodplains. 9. Channel--belt movements across floodplains. 10. Long--term, Large--scale Evolution of Fluvial Systems. 11. Fossils in Fluvial Deposits. Appendix 1. Methods of Measuring Bed Topography, Water flow, Sediment Transport, Erosion and Deposition in Rivers. Appendix 2. Methods of Describing and Interpreting Sedimentary Strata. References

@article{doi105860choice411567,
    title = "Rivers and floodplains: forms, processes, and sedimentary record",
    year = "2003",
    journal = "Choice Reviews Online",
    abstract = "1. Introduction. 2. Overview of River Systems. 3. Fundamentals of Water Flow. 4. Fundamentals of Sediment Transport. 5. Bed forms and Sedimentary Structures. 6. Alluvial Channels and Bars. 7. Floodplains. 8. Along--valley Variations in Channels and Floodplains. 9. Channel--belt movements across floodplains. 10. Long--term, Large--scale Evolution of Fluvial Systems. 11. Fossils in Fluvial Deposits. Appendix 1. Methods of Measuring Bed Topography, Water flow, Sediment Transport, Erosion and Deposition in Rivers. Appendix 2. Methods of Describing and Interpreting Sedimentary Strata. References",
    url = "https://doi.org/10.5860/choice.41-1567",
    doi = "10.5860/choice.41-1567",
    openalex = "W2912954225"
}

@article{s22fa152be16b999738a08a6c36284c0c4b5230fd7,
    title = "MONITORING LATERAL MOVEMENT AND STABILITY OF CHANNEL BANKS ON THE PEARL RIVER IN MISSISSIPPI D. Phil Turnipseed and James A. Smith U. S. Geological Survey, WRD",
    year = "2003",
    url = "https://www.semanticscholar.org/paper/2fa152be16b999738a08a6c36284c0c4b5230fd7",
    is_oa = "true",
    semanticscholar_id = "2fa152be16b999738a08a6c36284c0c4b5230fd7"
}

@misc{team2003conservation,
    author = "Team, MSRAP and undefined and undefined",
    title = "Conservation Planning in the Mississippi River Alluvial Plain",
    year = "2003",
    url = "https://doi.org/10.3411/col.04062122",
    doi = "10.3411/col.04062122",
    openalex = "W4246574560"
}

▪ Abstract Avulsion is the natural process by which flow diverts out of an established river channel into a new permanent course on the adjacent floodplain. Avulsions are primarily features of aggrading floodplains. Their recurrence interval varies widely among the few modern rivers for which such data exist, ranging from as low as 28 years for the Kosi River (India) to up to 1400 years for the Mississippi. Avulsions cause loss of life, property damage, destabilization of shipping and irrigation channels, and even coastal erosion as sediment is temporarily sequestered on the floodplain. They are also the main process that builds alluvial stratigraphy. Their causes remain relatively unknown, but stability analyses of bifurcating channels suggest that thresholds in the relative energy slope and Shields parameter of the bifurcating channel system are key factors.

@article{doi101146annurevearth32101802120201,
    author = "Slingerland, Rudy and Smith, Norman D.",
    title = "RIVER AVULSIONS AND THEIR DEPOSITS",
    year = "2004",
    journal = "Annual Review of Earth and Planetary Sciences",
    abstract = "▪ Abstract Avulsion is the natural process by which flow diverts out of an established river channel into a new permanent course on the adjacent floodplain. Avulsions are primarily features of aggrading floodplains. Their recurrence interval varies widely among the few modern rivers for which such data exist, ranging from as low as 28 years for the Kosi River (India) to up to 1400 years for the Mississippi. Avulsions cause loss of life, property damage, destabilization of shipping and irrigation channels, and even coastal erosion as sediment is temporarily sequestered on the floodplain. They are also the main process that builds alluvial stratigraphy. Their causes remain relatively unknown, but stability analyses of bifurcating channels suggest that thresholds in the relative energy slope and Shields parameter of the bifurcating channel system are key factors.",
    url = "https://doi.org/10.1146/annurev.earth.32.101802.120201",
    doi = "10.1146/annurev.earth.32.101802.120201",
    openalex = "W2139920049",
    references = "doi101002sici10969837199603213217aidesp61130co2u, doi101016001282527990059x, doi1010160037073869900104, doi101016s0012825200000386, doi101017s0022112081000451, doi101111j136530911965tb01561x, doi101111j136530911979tb00935x, doi101111j136530911989tb00817x, doi102307211375, doi10230740027956, flint1947geological"
}

Abstract The emphasis on gradient advantages in studies of avulsion is misleading. While gradient advantages are necessary for an avulsion to occur, the late Holocene avulsion history of the Mississippi River in Louisiana suggests that factors such as substrate composition and floodplain channel distributions are more important. Cross-valley to down-valley slope ratios of the modern floodplain range from 16 to 110 and are typically > 30. The slope ratio is 35 at the location of the Mississippi–Atchafalaya diversion (Old River) yet slope ratios are 83 to 110 immediately upvalley of Old River. All values of Mississippi River floodplain slope ratios are significantly larger than values of avulsion threshold calculated by numerical models. Shallow floodplain cores, 14C dating of organic remains, and geologic mapping show that the Mississippi River has avulsed only four times over the past 5 ky in the southern Lower Mississippi Valley (LMV). Gradient advantages are widespread, yet avulsions are rare. These observations indicate that factors other than gradient advantage control Mississippi River avulsion. Several examples of Mississippi and Red River avulsion by channel reoccupation support the idea that channel distributions and substrate compositions are primary influences on avulsion. Incipient Mississippi River avulsion and development of the Atchafalaya River involved reoccupation of abandoned Mississippi River channels and a Red River crevasse-splay complex. The modern Atchafalaya River also incises buried Mississippi River channel-belt sands. Abandoned channel belts and crevasse-splay complexes consist of sandy substrates that facilitate scour and the development of channels capable of capturing the Mississippi River. Abandoned channels provide ready-made conduits for Mississippi River flow that can efficiently develop into avulsive channels. Multi-storied sheet sandstones in ancient fluvial deposits may provide additional support for the idea that erodible substrates and floodplain channel distributions are critical influences on avulsion. These features record episodic reoccupation of channel belts, which at least in some cases, may simply reflect successive avulsions rather than major changes in aggradation rate or extrabasinal factors such as climate.

@article{doi102110jsr2005053,
    author = "Aslan, Andres and Autin, W. J. and Blum, M. D.",
    title = "Causes of River Avulsion: Insights from the Late Holocene Avulsion History of the Mississippi River, U.S.A.",
    year = "2005",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract The emphasis on gradient advantages in studies of avulsion is misleading. While gradient advantages are necessary for an avulsion to occur, the late Holocene avulsion history of the Mississippi River in Louisiana suggests that factors such as substrate composition and floodplain channel distributions are more important. Cross-valley to down-valley slope ratios of the modern floodplain range from 16 to 110 and are typically > 30. The slope ratio is 35 at the location of the Mississippi–Atchafalaya diversion (Old River) yet slope ratios are 83 to 110 immediately upvalley of Old River. All values of Mississippi River floodplain slope ratios are significantly larger than values of avulsion threshold calculated by numerical models. Shallow floodplain cores, 14C dating of organic remains, and geologic mapping show that the Mississippi River has avulsed only four times over the past 5 ky in the southern Lower Mississippi Valley (LMV). Gradient advantages are widespread, yet avulsions are rare. These observations indicate that factors other than gradient advantage control Mississippi River avulsion. Several examples of Mississippi and Red River avulsion by channel reoccupation support the idea that channel distributions and substrate compositions are primary influences on avulsion. Incipient Mississippi River avulsion and development of the Atchafalaya River involved reoccupation of abandoned Mississippi River channels and a Red River crevasse-splay complex. The modern Atchafalaya River also incises buried Mississippi River channel-belt sands. Abandoned channel belts and crevasse-splay complexes consist of sandy substrates that facilitate scour and the development of channels capable of capturing the Mississippi River. Abandoned channels provide ready-made conduits for Mississippi River flow that can efficiently develop into avulsive channels. Multi-storied sheet sandstones in ancient fluvial deposits may provide additional support for the idea that erodible substrates and floodplain channel distributions are critical influences on avulsion. These features record episodic reoccupation of channel belts, which at least in some cases, may simply reflect successive avulsions rather than major changes in aggradation rate or extrabasinal factors such as climate.",
    url = "https://doi.org/10.2110/jsr.2005.053",
    doi = "10.2110/jsr.2005.053",
    openalex = "W2162597581",
    references = "doi102110jsr69800, openalexw1846023905"
}

Abstract The Nolan site (16MA201), 14 C dated 5200–4800 cal yr B.P. and located in the Tensas Basin of northeastern Louisiana, is the only recorded Middle Archaic mound site in the alluvial valley of the Mississippi River. Alluvial deposition has buried the Nolan site under 3–4 m of Holocene sediment, prohibiting traditional excavation of the site. Because data are unattainable by other means, soil coring and subsequent stratigraphic and sedimentological analyses permit reconstruction of the natural and cultural depositional history of the Nolan site. The sedimentary characteristics of basal deposits within cores suggest the presence of an Arkansas River paleochannel immediately adjacent to the site. Chronostratigraphic data show this channel was no longer active by ca. 5200 cal yr B.P. Contrary to existing models, the Arkansas River Meander Belt 4 and the Mississippi River Meander Belt 4 are not the same age. Microartifact and losson‐ignition analyses of sediment identify natural versus cultural strata and permit the identification of artificial constructions—including four earthen mounds and one earthen ridge—at the Nolan site. Overbank sediments attributed to a mapped Mississippi River Stage 4 meander belt are dated ca. 4800–3800 cal yr B.P. This age is considerably younger than previous estimates and demonstrates the existing chronological models for Mississippi River meander belts must be carefully assessed. Core analyses also reveal flood‐related crevasse splays deposited throughout the Tensas Basin after the occupation of the Nolan site. These deposits serve as relative chronological indicators and aid in stratigraphic assessments of the Nolan site. Reconstruction of the earthworks and their stratigraphic context reveals one of the largest and earliest Middle Archaic mound sites in North America. © 2006 Wiley Periodicals, Inc.

@article{doi101002gea20125,
    author = "Arco, Lee J. and Adelsberger, Katherine A. and Hung, Ling‐yu and Kidder, Tristram R.",
    title = "Alluvial geoarchaeology of a Middle Archaic Mound complex in the lower Mississippi Valley, U.S.A.",
    year = "2006",
    journal = "Geoarchaeology",
    abstract = "Abstract The Nolan site (16MA201), 14 C dated 5200–4800 cal yr B.P. and located in the Tensas Basin of northeastern Louisiana, is the only recorded Middle Archaic mound site in the alluvial valley of the Mississippi River. Alluvial deposition has buried the Nolan site under 3–4 m of Holocene sediment, prohibiting traditional excavation of the site. Because data are unattainable by other means, soil coring and subsequent stratigraphic and sedimentological analyses permit reconstruction of the natural and cultural depositional history of the Nolan site. The sedimentary characteristics of basal deposits within cores suggest the presence of an Arkansas River paleochannel immediately adjacent to the site. Chronostratigraphic data show this channel was no longer active by ca. 5200 cal yr B.P. Contrary to existing models, the Arkansas River Meander Belt 4 and the Mississippi River Meander Belt 4 are not the same age. Microartifact and losson‐ignition analyses of sediment identify natural versus cultural strata and permit the identification of artificial constructions—including four earthen mounds and one earthen ridge—at the Nolan site. Overbank sediments attributed to a mapped Mississippi River Stage 4 meander belt are dated ca. 4800–3800 cal yr B.P. This age is considerably younger than previous estimates and demonstrates the existing chronological models for Mississippi River meander belts must be carefully assessed. Core analyses also reveal flood‐related crevasse splays deposited throughout the Tensas Basin after the occupation of the Nolan site. These deposits serve as relative chronological indicators and aid in stratigraphic assessments of the Nolan site. Reconstruction of the earthworks and their stratigraphic context reveals one of the largest and earliest Middle Archaic mound sites in North America. © 2006 Wiley Periodicals, Inc.",
    url = "https://doi.org/10.1002/gea.20125",
    doi = "10.1002/gea.20125",
    openalex = "W2125860845",
    references = "doi101016s0013795296000245, smith1996fluvial"
}

Abstract Using modern and ancient examples we show that river-dominated deltas formed in shallow basins have multiple coeval terminal distributary channels at different scales. Sediment dispersion through multiple terminal distributary channels results in an overall lobate shape of the river-dominated delta that is opposite to the digitate Mississippi type, but similar with deltas described as wave-dominated. The examples of deltas that we present show typical coarsening-upward delta-front facies successions but do not contain deep distributary channels, as have been routinely interpreted in many ancient deltas. We show that shallow-water river-dominated delta-front deposits are typically capped by small terminal distributary channels, the cross-sectional area of which represents a small fraction of the main fluvial trunk channel. Recognizing terminal distributary channels is critical in interpretation of river-dominated deltas. Terminal distributary channels are the most distal channelized features and can be both subaerial and subaqueous. Their dimensions vary between tens of meters to kilometers in width, with common values of 100–400 m and depths of 1–3 m, and are rarely incised. The orientation of the terminal distributary channels for the same system has a large variation, with values between 123° (Volga Delta) and 248° (Lena Delta). Terminal distributary channels are intimately associated with mouth-bar deposits and are infilled by aggradation and lateral or upstream migration of the mouth bars. Deposits of terminal distributary channels have characteristic sedimentary structures of unidirectional effluent flow but also show evidence of reworking by waves and tides.

@article{doi102110jsr2006026,
    author = "Olariu, Cornel and Bhattacharya, Janok P.",
    title = "Terminal Distributary Channels and Delta Front Architecture of River-Dominated Delta Systems",
    year = "2006",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract Using modern and ancient examples we show that river-dominated deltas formed in shallow basins have multiple coeval terminal distributary channels at different scales. Sediment dispersion through multiple terminal distributary channels results in an overall lobate shape of the river-dominated delta that is opposite to the digitate Mississippi type, but similar with deltas described as wave-dominated. The examples of deltas that we present show typical coarsening-upward delta-front facies successions but do not contain deep distributary channels, as have been routinely interpreted in many ancient deltas. We show that shallow-water river-dominated delta-front deposits are typically capped by small terminal distributary channels, the cross-sectional area of which represents a small fraction of the main fluvial trunk channel. Recognizing terminal distributary channels is critical in interpretation of river-dominated deltas. Terminal distributary channels are the most distal channelized features and can be both subaerial and subaqueous. Their dimensions vary between tens of meters to kilometers in width, with common values of 100–400 m and depths of 1–3 m, and are rarely incised. The orientation of the terminal distributary channels for the same system has a large variation, with values between 123° (Volga Delta) and 248° (Lena Delta). Terminal distributary channels are intimately associated with mouth-bar deposits and are infilled by aggradation and lateral or upstream migration of the mouth bars. Deposits of terminal distributary channels have characteristic sedimentary structures of unidirectional effluent flow but also show evidence of reworking by waves and tides.",
    url = "https://doi.org/10.2110/jsr.2006.026",
    doi = "10.2110/jsr.2006.026",
    openalex = "W2132272817",
    references = "doi101306111302730367, doi1013065ceadd7616bb11d78645000102c1865d, openalexw101633874, openalexw1558464430, openalexw1592594904"
}

Abstract The three-dimensional geometry of fluvial channel bodies and valley fills has received much less attention than their internal structure, despite the fact that many subsurface analyses draw upon the geometry of suitable fluvial analogues. Although channel-body geometry has been widely linked to base-level change and accommodation, few studies have evaluated the influence of local geomorphic controls. To remedy these deficiencies, we review the terminology for describing channel-body geometry, and present a literature dataset that represents more than 1500 bedrock and Quaternary fluvial bodies for which width (W) and thickness (T) are recorded. Twelve types of channel bodies and valley fills are distinguished based on their geomorphic setting, geometry, and internal structure, and log-log plots of W against T are presented for each type. Narrow and broad ribbons (W/T 1000, respectively) are distinguished. The dataset allows an informed selection of analogues for subsurface applications, and spreadsheets and graphs can be downloaded from a data repository. Mobile-channel belts are mainly the deposits of braided and low-sinuosity rivers, which may exceed 1 km in composite thickness and 1300 km in width. Their overwhelming dominance throughout geological time reflects their link to tectonic activity, exhumation events, and high sediment supply. Some deposits that rest on flat-lying bedrock unconformities cover areas > 70,000 km2. In contrast, meandering river bodies in the dataset are < 38 m thick and < 15 km wide, and the organized flow conditions necessary for their development may have been unusual. They do not appear to have built basin-scale deposits. Fixed channels and poorly channelized systems are divided into distributary systems (channels on megafans, deltas, and distal alluvial fans, and in crevasse systems and avulsion deposits), through-going rivers, and channels in eolian settings. Because width/maximum depth of many modern alluvial channels is between 5 and 15, these bodies probably record an initial aspect ratio followed by modest widening prior to filling or avulsion. The narrow form (W/T typically < 15) commonly reflects bank resistance and rapid filling, although some are associated with base-level rise. Exceptionally narrow bodies (W/T locally < 1) may additionally reflect unusually deep incision, compactional thickening, filling by mass-flow deposits, balanced aggradation of natural levees and channels, thawing of frozen substrates, and channel reoccupation. Valley fills rest on older bedrock or represent a brief hiatus within marine and alluvial successions. Many bedrock valley fills have W/T < 20 due to deep incision along tectonic lineaments and stacking along faults. Within marine and alluvial strata, upper Paleozoic valley fills appear larger than Mesozoic examples, possibly reflecting the influence of large glacioeustatic fluctuations in the Paleozoic. Valley fills in sub-glacial and proglacial settings are relatively narrow (W/T as low as 2.5) due to incision from catastrophic meltwater flows. The overlap in dimensions between channel bodies and valley fills, as identified by the original authors, suggests that many braided and meandering channel bodies in the rock record occupy paleovalleys. Modeling has emphasized the importance of avulsion frequency, sedimentation rate, and the ratio of channel belt and floodplain width in determining channel-body connectedness. Although these controls strongly influence mobile channel belts, they are less effective in fixed-channel systems, for which many database examples testify to the influence of local geomorphic factors that include bank strength and channel aggradation. The dataset contains few examples of highly connected suites of fixed-channel bodies, despite their abundance in many formations. Whereas accommodation is paramount for preservation, its influence is mediated through geomorphic factors, thus complicating inferences about base-level controls.

@article{doi102110jsr2006060,
    author = "Gibling, Martin R.",
    title = "Width and Thickness of Fluvial Channel Bodies and Valley Fills in the Geological Record: A Literature Compilation and Classification",
    year = "2006",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract The three-dimensional geometry of fluvial channel bodies and valley fills has received much less attention than their internal structure, despite the fact that many subsurface analyses draw upon the geometry of suitable fluvial analogues. Although channel-body geometry has been widely linked to base-level change and accommodation, few studies have evaluated the influence of local geomorphic controls. To remedy these deficiencies, we review the terminology for describing channel-body geometry, and present a literature dataset that represents more than 1500 bedrock and Quaternary fluvial bodies for which width (W) and thickness (T) are recorded. Twelve types of channel bodies and valley fills are distinguished based on their geomorphic setting, geometry, and internal structure, and log-log plots of W against T are presented for each type. Narrow and broad ribbons (W/T 1000, respectively) are distinguished. The dataset allows an informed selection of analogues for subsurface applications, and spreadsheets and graphs can be downloaded from a data repository. Mobile-channel belts are mainly the deposits of braided and low-sinuosity rivers, which may exceed 1 km in composite thickness and 1300 km in width. Their overwhelming dominance throughout geological time reflects their link to tectonic activity, exhumation events, and high sediment supply. Some deposits that rest on flat-lying bedrock unconformities cover areas > 70,000 km2. In contrast, meandering river bodies in the dataset are < 38 m thick and < 15 km wide, and the organized flow conditions necessary for their development may have been unusual. They do not appear to have built basin-scale deposits. Fixed channels and poorly channelized systems are divided into distributary systems (channels on megafans, deltas, and distal alluvial fans, and in crevasse systems and avulsion deposits), through-going rivers, and channels in eolian settings. Because width/maximum depth of many modern alluvial channels is between 5 and 15, these bodies probably record an initial aspect ratio followed by modest widening prior to filling or avulsion. The narrow form (W/T typically < 15) commonly reflects bank resistance and rapid filling, although some are associated with base-level rise. Exceptionally narrow bodies (W/T locally < 1) may additionally reflect unusually deep incision, compactional thickening, filling by mass-flow deposits, balanced aggradation of natural levees and channels, thawing of frozen substrates, and channel reoccupation. Valley fills rest on older bedrock or represent a brief hiatus within marine and alluvial successions. Many bedrock valley fills have W/T < 20 due to deep incision along tectonic lineaments and stacking along faults. Within marine and alluvial strata, upper Paleozoic valley fills appear larger than Mesozoic examples, possibly reflecting the influence of large glacioeustatic fluctuations in the Paleozoic. Valley fills in sub-glacial and proglacial settings are relatively narrow (W/T as low as 2.5) due to incision from catastrophic meltwater flows. The overlap in dimensions between channel bodies and valley fills, as identified by the original authors, suggests that many braided and meandering channel bodies in the rock record occupy paleovalleys. Modeling has emphasized the importance of avulsion frequency, sedimentation rate, and the ratio of channel belt and floodplain width in determining channel-body connectedness. Although these controls strongly influence mobile channel belts, they are less effective in fixed-channel systems, for which many database examples testify to the influence of local geomorphic factors that include bank strength and channel aggradation. The dataset contains few examples of highly connected suites of fixed-channel bodies, despite their abundance in many formations. Whereas accommodation is paramount for preservation, its influence is mediated through geomorphic factors, thus complicating inferences about base-level controls.",
    url = "https://doi.org/10.2110/jsr.2006.060",
    doi = "10.2110/jsr.2006.060",
    openalex = "W2113298788",
    references = "doi1010079783662032374, doi1010160012825285900017, doi1010160037073878900027, doi1010160037073884900745, doi1010160169555x9290039q, doi1010160341816294900019, doi101016s003707380100118x, doi101029jd092id07p08411, doi101046j13653091200000008x, doi101086626637, doi101111j136530911989tb00817x, doi10113000167606194556275edosat20co2, doi101144gsjgs13610039, doi101306703c8f01170711d78645000102c1865d, doi102110csp9907, doi102110jsr69800, doi102307211375, flint1947geological, openalexw2094255421"
}

During the spring of 2004, water levels were measured in 684 wells completed in the Mississippi River Valley alluvial aquifer in eastern Arkansas. Ground-water levels are affected by intense ground-water withdrawals resulting in extensive potentiometric depressions. In 2004, the highest water-level altitude measured was 293 feet above National Geodetic Vertical Datum of 1929 in northeastern Clay County. The lowest water-level altitude measured was 76 feet above National Geodetic Vertical Datum of 1929 in the center of Arkansas County. A large depression in the potentiometric surface was located in Arkansas, Lonoke, and Prairie Counties during 1998 and persisted to 2002. The area enclosed in the 100-foot contour in Arkansas County in 2004 is about the same as in 2002, however, the area enclosed in the 100-foot contour in Lonoke and Prairie Counties in 2004 has receded. Two shallower cones of depressions were located in Craighead, Cross, and Poinsett Counties and St. Francis, Woodruff, Lee, and Monroe Counties west of Crowleys Ridge during 1998. The 2004 potentiometricsurface map shows that the areas enclosed by the 140-foot contour have continued to expand. A map of changes in water-level measurements between 2000 and 2004 was constructed using the difference between water-level measurements from 625 wells reported in this report and the 2000 Mississippi River Valley alluvial aquifer report. Water-level changes between 2000 and 2004 ranged from -31.1 feet to 16.3 feet, with a mean of -0.7 feet (negative changes indicating water-level declines, positive changes indicating water-level rises). The largest rise of 16.3 feet is in Arkansas County and the largest decline of -31.1 feet is in Prairie County. Long-term water-level changes were calculated for 134 wells in the alluvial aquifer for the period from 1980 to 2004. The mean annual decline in water level for the entire study area was -0.31 feet per year with a range of -1.35 feet per year to 0.84 feet per year. The analysis of long-term water-level changes (1980-2004) in the depression in Arkansas and Prairie Counties shows the effects of the elongation of this depression. Water samples were collected from 138 wells completed in the alluvial aquifer and measured onsite for specific conductance and temperature. Samples were collected at 71 wells for dissolved chloride analysis at the U.S. Geological Survey National Water Quality Laboratory. Specific conductance ranged from 205 microsiemens per centimeter at 25 degrees Celsius at a well in Lonoke County to 1,440 microsiemens per centimeter at 25 degrees Celsius at a well in Monroe County.

@article{doi103133sir20065128,
    author = "Schrader, T.P.",
    title = "Status of Water Levels and Selected Water-Quality Conditions in the Mississippi River Valley Alluvial Aquifer in Eastern Arkansas, 2004",
    year = "2006",
    journal = "Scientific investigations report",
    abstract = "During the spring of 2004, water levels were measured in 684 wells completed in the Mississippi River Valley alluvial aquifer in eastern Arkansas. Ground-water levels are affected by intense ground-water withdrawals resulting in extensive potentiometric depressions. In 2004, the highest water-level altitude measured was 293 feet above National Geodetic Vertical Datum of 1929 in northeastern Clay County. The lowest water-level altitude measured was 76 feet above National Geodetic Vertical Datum of 1929 in the center of Arkansas County. A large depression in the potentiometric surface was located in Arkansas, Lonoke, and Prairie Counties during 1998 and persisted to 2002. The area enclosed in the 100-foot contour in Arkansas County in 2004 is about the same as in 2002, however, the area enclosed in the 100-foot contour in Lonoke and Prairie Counties in 2004 has receded. Two shallower cones of depressions were located in Craighead, Cross, and Poinsett Counties and St. Francis, Woodruff, Lee, and Monroe Counties west of Crowleys Ridge during 1998. The 2004 potentiometricsurface map shows that the areas enclosed by the 140-foot contour have continued to expand. A map of changes in water-level measurements between 2000 and 2004 was constructed using the difference between water-level measurements from 625 wells reported in this report and the 2000 Mississippi River Valley alluvial aquifer report. Water-level changes between 2000 and 2004 ranged from -31.1 feet to 16.3 feet, with a mean of -0.7 feet (negative changes indicating water-level declines, positive changes indicating water-level rises). The largest rise of 16.3 feet is in Arkansas County and the largest decline of -31.1 feet is in Prairie County. Long-term water-level changes were calculated for 134 wells in the alluvial aquifer for the period from 1980 to 2004. The mean annual decline in water level for the entire study area was -0.31 feet per year with a range of -1.35 feet per year to 0.84 feet per year. The analysis of long-term water-level changes (1980-2004) in the depression in Arkansas and Prairie Counties shows the effects of the elongation of this depression. Water samples were collected from 138 wells completed in the alluvial aquifer and measured onsite for specific conductance and temperature. Samples were collected at 71 wells for dissolved chloride analysis at the U.S. Geological Survey National Water Quality Laboratory. Specific conductance ranged from 205 microsiemens per centimeter at 25 degrees Celsius at a well in Lonoke County to 1,440 microsiemens per centimeter at 25 degrees Celsius at a well in Monroe County.",
    url = "https://doi.org/10.3133/sir20065128",
    doi = "10.3133/sir20065128",
    openalex = "W1586812420"
}

The lower Mississippi valley contains multiple large braid belts for which age control has been limited. Application of the optically stimulated luminescence technique has produced a new chronology of lower Mississippi valley channel-belt formation and insight into the valley's evolution during the last glacial cycle. Fluvial deposits range from last interglacial meander belts (85 ± 7 to 83 ± 7 ka) to multiple braid belts (64 ± 5 to 11 ± 1 ka) and record large-amplitude responses of the Mississippi River to glacially induced changes in discharge and sediment supply during the last glacial cycle. Slackwater deposits in buried tributary valleys from the middle Mississippi valley and northern lower Mississippi valley suggest that the river was flowing at a position 8–21 m below the present flood plain during the last interglacial, then rapidly aggraded and switched to a braided regime to form the highest and oldest braid belt by 64 ± 5 to 50 ± 4 ka, coincident with initial glaciation of the upper drainage basin. The Mississippi River remained braided until final meltwater withdrawal from its headwaters in the earliest Holocene. Braid-belt formation and incision was controlled by fluctuations in meltwater and sediment discharge, while glacio-eustatic sea level controlled the elevation to which the river was graded, causing late glacial braid belts to dip below the Holocene flood plain in the southern lower Mississippi valley. Moreover, avulsions in the middle Mississippi valley and northern lower Mississippi valley during the last glaciation have pinned the river over regions of shallow bedrock, preventing the modern river from incising to its last interglacial profile. The new chronology and longitudinal profiles presented here provide insight into the response of this continental-scale river system to climatic (glacial) and base-level forcing during the last 100 k.y. glacial cycle.

@article{doi101130b259341,
    author = "Rittenour, Tammy M. and Blum, Michael D. and Goble, Ronald J.",
    title = "Fluvial evolution of the lower Mississippi River valley during the last 100 k.y. glacial cycle: Response to glaciation and sea-level change",
    year = "2007",
    journal = "Geological Society of America Bulletin",
    abstract = "The lower Mississippi valley contains multiple large braid belts for which age control has been limited. Application of the optically stimulated luminescence technique has produced a new chronology of lower Mississippi valley channel-belt formation and insight into the valley's evolution during the last glacial cycle. Fluvial deposits range from last interglacial meander belts (85 ± 7 to 83 ± 7 ka) to multiple braid belts (64 ± 5 to 11 ± 1 ka) and record large-amplitude responses of the Mississippi River to glacially induced changes in discharge and sediment supply during the last glacial cycle. Slackwater deposits in buried tributary valleys from the middle Mississippi valley and northern lower Mississippi valley suggest that the river was flowing at a position 8–21 m below the present flood plain during the last interglacial, then rapidly aggraded and switched to a braided regime to form the highest and oldest braid belt by 64 ± 5 to 50 ± 4 ka, coincident with initial glaciation of the upper drainage basin. The Mississippi River remained braided until final meltwater withdrawal from its headwaters in the earliest Holocene. Braid-belt formation and incision was controlled by fluctuations in meltwater and sediment discharge, while glacio-eustatic sea level controlled the elevation to which the river was graded, causing late glacial braid belts to dip below the Holocene flood plain in the southern lower Mississippi valley. Moreover, avulsions in the middle Mississippi valley and northern lower Mississippi valley during the last glaciation have pinned the river over regions of shallow bedrock, preventing the modern river from incising to its last interglacial profile. The new chronology and longitudinal profiles presented here provide insight into the response of this continental-scale river system to climatic (glacial) and base-level forcing during the last 100 k.y. glacial cycle.",
    url = "https://doi.org/10.1130/b25934.1",
    doi = "10.1130/b25934.1",
    openalex = "W1977594215",
    references = "doi102110jsr69800"
}

Abstract Over the past decades, many studies have focused on the dimensions of channel-belt sand bodies (referred to as belts) in fluvial deposits because of their relevance for hydrocarbon exploration and production. Some field studies have revealed a significant downstream decrease of channel-belt width and width/thickness ratio along the length of the channel belt. To verify whether this is a common feature in fluviodeltaic settings, eight Holocene channel belts in the Rhine–Meuse delta (The Netherlands) were selected and one in the Lower Mississippi Valley (U.S.A.). We determined channel-belt geometry (width or width/thickness ratio) using geological–geomorphological maps and detailed cross sections based on borings. It was found that the width of channel belts encased in cohesive deposits decreases by a factor of 4 to 6.5 in a downstream direction along the length of the channel belts. The width/thickness ratio decreases by a factor of 2.5 to 5. On the other hand, the width of a channel belt incised in a noncohesive substrate remains constant along its entire course. These observations are related to longitudinal changes in and power. It is suggested that is the dominating factor determining the geometric properties of channel belts, and the variability therein, at least in the Rhine–Meuse delta. The currently available alluvial-architecture models most likely overestimate sand quantities and connectedness in alluvial successions, because channel-belt dimensions are held constant in all models. We therefore propose that the factors bank erodibility and stream power, which influence width and width/thickness ratio of channel belts, should be incorporated in future alluvial-architecture models in order to make more realistic estimates of sand quantities in river deltas.

@article{doi102110jsr2007013,
    author = "Gouw, M.J.P. and Berendsen, H.J.A.",
    title = "Variability of Channel-Belt Dimensions and the Consequences for Alluvial Architecture: Observations from the Holocene Rhine-Meuse Delta (The Netherlands) and Lower Mississippi Valley (U.S.A.)",
    year = "2007",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract Over the past decades, many studies have focused on the dimensions of channel-belt sand bodies (referred to as belts) in fluvial deposits because of their relevance for hydrocarbon exploration and production. Some field studies have revealed a significant downstream decrease of channel-belt width and width/thickness ratio along the length of the channel belt. To verify whether this is a common feature in fluviodeltaic settings, eight Holocene channel belts in the Rhine–Meuse delta (The Netherlands) were selected and one in the Lower Mississippi Valley (U.S.A.). We determined channel-belt geometry (width or width/thickness ratio) using geological–geomorphological maps and detailed cross sections based on borings. It was found that the width of channel belts encased in cohesive deposits decreases by a factor of 4 to 6.5 in a downstream direction along the length of the channel belts. The width/thickness ratio decreases by a factor of 2.5 to 5. On the other hand, the width of a channel belt incised in a noncohesive substrate remains constant along its entire course. These observations are related to longitudinal changes in and power. It is suggested that is the dominating factor determining the geometric properties of channel belts, and the variability therein, at least in the Rhine–Meuse delta. The currently available alluvial-architecture models most likely overestimate sand quantities and connectedness in alluvial successions, because channel-belt dimensions are held constant in all models. We therefore propose that the factors bank erodibility and stream power, which influence width and width/thickness ratio of channel belts, should be incorporated in future alluvial-architecture models in order to make more realistic estimates of sand quantities in river deltas.",
    url = "https://doi.org/10.2110/jsr.2007.013",
    doi = "10.2110/jsr.2007.013",
    openalex = "W2113721243",
    references = "doi101016s0013795296000245"
}

Digital surfaces of selected Tertiary and younger age hydrogeologic units within the Mississippi embayment aquifer system were created using more than 2,600 geophysical logs for an area that covers approximately 70,000 square miles and encompasses parts of eight states. The digital surfaces were developed to define and display the hydrogeologic framework for the Mississippi Embayment Regional Aquifer Study (MERAS). The digital surfaces also provide a foundation of the selected hydrogeologic units for development of a steady-state and transient regional ground-water flow model of the Mississippi embayment aquifer system from the top of the Midway confining unit upwards to land surface. The ground-water flow model is under development as part of the U.S. Geological Survey Ground-Water Resources Program. Using a Geographic Information System, nine digital surfaces of the tops of selected hydrogeologic units were created using the Australian National University Digital Elevation Model method as an interpolation scheme. Thickness maps also were constructed using the Geographic Information System by calculating the difference between the altitude of the interpreted base of an overlying unit and the altitude of the interpreted top of an underlying unit. In general, the highest hydrogeologic unit altitudes are located along the eastern edge of the study area in the outcrop, and the lowest altitudes, in general, are located along the southern edge of the study area along the axis of the embayment. The Mississippi River Valley alluvial aquifer and the lower Claiborne aquifer are the thinnest aquifers of importance in the study area; the thickest aquifer of importance is the middle Claiborne aquifer.

@article{doi103133sir20085098,
    author = "Hart, Rheannon M. and Clark, Brian R. and Bolyard, Susan E.",
    title = "Digital surfaces and thicknesses of selected hydrogeologic units within the Mississippi Embayment Regional Aquifer Study (MERAS)",
    year = "2008",
    journal = "Scientific investigations report",
    abstract = "Digital surfaces of selected Tertiary and younger age hydrogeologic units within the Mississippi embayment aquifer system were created using more than 2,600 geophysical logs for an area that covers approximately 70,000 square miles and encompasses parts of eight states. The digital surfaces were developed to define and display the hydrogeologic framework for the Mississippi Embayment Regional Aquifer Study (MERAS). The digital surfaces also provide a foundation of the selected hydrogeologic units for development of a steady-state and transient regional ground-water flow model of the Mississippi embayment aquifer system from the top of the Midway confining unit upwards to land surface. The ground-water flow model is under development as part of the U.S. Geological Survey Ground-Water Resources Program. Using a Geographic Information System, nine digital surfaces of the tops of selected hydrogeologic units were created using the Australian National University Digital Elevation Model method as an interpolation scheme. Thickness maps also were constructed using the Geographic Information System by calculating the difference between the altitude of the interpreted base of an overlying unit and the altitude of the interpreted top of an underlying unit. In general, the highest hydrogeologic unit altitudes are located along the eastern edge of the study area in the outcrop, and the lowest altitudes, in general, are located along the southern edge of the study area along the axis of the embayment. The Mississippi River Valley alluvial aquifer and the lower Claiborne aquifer are the thinnest aquifers of importance in the study area; the thickest aquifer of importance is the middle Claiborne aquifer.",
    url = "https://doi.org/10.3133/sir20085098",
    doi = "10.3133/sir20085098",
    openalex = "W74145975"
}

The Mississippi Embayment Regional Aquifer Study (MERAS) was conducted with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater. This report documents the construction and calibration of a finite-difference groundwater model for use as a tool to quantify groundwater availability within the Mississippi embayment. To approximate the differential equation, the MERAS model was constructed with the U.S. Geological Survey's modular three-dimensional finite-difference code, MODFLOW-2005; the preconditioned conjugate gradient solver within MODFLOW-2005 was used for the numerical solution technique. The model area boundary is approximately 78,000 square miles and includes eight States with approximately 6,900 miles of simulated streams, 70,000 well locations, and 10 primary hydrogeologic units. The finite-difference grid consists of 414 rows, 397 columns, and 13 layers. Each model cell is 1 square mile with varying thickness by cell and by layer. The simulation period extends from January 1, 1870, to April 1, 2007, for a total of 137 years and 69 stress periods. The first stress period is simulated as steady state to represent predevelopment conditions. Areal recharge is applied throughout the MERAS model area using the MODFLOW-2005 Recharge Package. Irrigation, municipal, and industrial wells are simulated using the Multi-Node Well Package. There are 43 streams simulated by the MERAS model. Each stream or river in the model area was simulated using the Streamflow-Routing Package. The perimeter of the model area and the base of the flow system are represented as no-flow boundaries. The downgradient limit of each model layer is a no-flow boundary, which approximates the extent of water with less than 10,000 milligrams per liter of dissolved solids. The MERAS model was calibrated by making manual changes to parameter values and examining residuals for hydraulic heads and streamflow. Additional calibration was achieved through alternate use of UCODE-2005 and PEST. Simulated heads were compared to 55,786 hydraulic-head measurements from 3,245 wells in the MERAS model area. Values of root mean square error between simulated and observed hydraulic heads of all observations ranged from 8.33 feet in 1919 to 47.65 feet in 1951, though only six root mean square error values are greater than 40 feet for the entire simulation period. Simulated streamflow generally is lower than measured streamflow for streams with streamflow less than 1,000 cubic feet per second, and greater than measured streamflow for streams with streamflow more than 1,000 cubic feet per second. Simulated streamflow is underpredicted for 18 observations and overpredicted for 10 observations in the model. These differences in streamflow illustrate the large uncertainty in model inputs such as predevelopment recharge, overland flow, pumpage (from stream and aquifer), precipitation, and observation weights. The groundwater-flow budget indicates changes in flow into (inflows) and out of (outflows) the model area during the pregroundwater-irrigation period (pre-1870) to 2007. Total flow (sum of inflows or outflows) through the model ranged from about 600 million gallons per day prior to development to 18,197 million gallons per day near the end of the simulation. The pumpage from wells represents the largest outflow components with a net rate of 18,197 million gallons per day near the end of the model simulation in 2006. Groundwater outflows are offset primarily by inflow from aquifer storage and recharge.

@article{doi103133sir20095172,
    author = "Clark, Brian R. and Hart, Rheannon M.",
    title = "The Mississippi Embayment Regional Aquifer Study (MERAS): Documentation of a groundwater-flow model constructed to assess water availability in the Mississippi embayment",
    year = "2009",
    journal = "Scientific investigations report",
    abstract = "The Mississippi Embayment Regional Aquifer Study (MERAS) was conducted with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater. This report documents the construction and calibration of a finite-difference groundwater model for use as a tool to quantify groundwater availability within the Mississippi embayment. To approximate the differential equation, the MERAS model was constructed with the U.S. Geological Survey's modular three-dimensional finite-difference code, MODFLOW-2005; the preconditioned conjugate gradient solver within MODFLOW-2005 was used for the numerical solution technique. The model area boundary is approximately 78,000 square miles and includes eight States with approximately 6,900 miles of simulated streams, 70,000 well locations, and 10 primary hydrogeologic units. The finite-difference grid consists of 414 rows, 397 columns, and 13 layers. Each model cell is 1 square mile with varying thickness by cell and by layer. The simulation period extends from January 1, 1870, to April 1, 2007, for a total of 137 years and 69 stress periods. The first stress period is simulated as steady state to represent predevelopment conditions. Areal recharge is applied throughout the MERAS model area using the MODFLOW-2005 Recharge Package. Irrigation, municipal, and industrial wells are simulated using the Multi-Node Well Package. There are 43 streams simulated by the MERAS model. Each stream or river in the model area was simulated using the Streamflow-Routing Package. The perimeter of the model area and the base of the flow system are represented as no-flow boundaries. The downgradient limit of each model layer is a no-flow boundary, which approximates the extent of water with less than 10,000 milligrams per liter of dissolved solids. The MERAS model was calibrated by making manual changes to parameter values and examining residuals for hydraulic heads and streamflow. Additional calibration was achieved through alternate use of UCODE-2005 and PEST. Simulated heads were compared to 55,786 hydraulic-head measurements from 3,245 wells in the MERAS model area. Values of root mean square error between simulated and observed hydraulic heads of all observations ranged from 8.33 feet in 1919 to 47.65 feet in 1951, though only six root mean square error values are greater than 40 feet for the entire simulation period. Simulated streamflow generally is lower than measured streamflow for streams with streamflow less than 1,000 cubic feet per second, and greater than measured streamflow for streams with streamflow more than 1,000 cubic feet per second. Simulated streamflow is underpredicted for 18 observations and overpredicted for 10 observations in the model. These differences in streamflow illustrate the large uncertainty in model inputs such as predevelopment recharge, overland flow, pumpage (from stream and aquifer), precipitation, and observation weights. The groundwater-flow budget indicates changes in flow into (inflows) and out of (outflows) the model area during the pregroundwater-irrigation period (pre-1870) to 2007. Total flow (sum of inflows or outflows) through the model ranged from about 600 million gallons per day prior to development to 18,197 million gallons per day near the end of the simulation. The pumpage from wells represents the largest outflow components with a net rate of 18,197 million gallons per day near the end of the model simulation in 2006. Groundwater outflows are offset primarily by inflow from aquifer storage and recharge.",
    url = "https://doi.org/10.3133/sir20095172",
    doi = "10.3133/sir20095172",
    openalex = "W1561995978",
    references = "doi103133wsp2292"
}

Abstract An analysis of remotely sensed imagery reveals that fluvial planform geometries within aggrading continental areas are dominated by distributive fluvial systems (DFSs). We documented the gradient, length, apex location, planform, termination type, and tectonic and climatic setting of 415 examples of fluvial systems which in planform display a radial, distributive channel pattern and have an apex–toe distance &gt; 30 km (large DFSs). The longest of these DFSs is 704 km in length, with the majority (72%) ranging between 30 and 100 km in length. Gradients on individual systems range from 0.00003 (0.0018°) to 0.02656 (1.5°). Six planform types are recognized, those with: (1) a single braided channel that bifurcates downstream into braided and/or straight channels, (2) a single dominant braided channel, (3) a single dominant braided channel which becomes sinuous downstream often bifurcating, (4) a single dominant sinuous channel, (5) a single sinuous channel that bifurcates downstream into smaller sinuous channels, and (6) multiple sinuous channels. Of the studied examples 58% occur within exorheic basins and 42% in endorheic basins, with seven different termination types recognized. In many examples, channel planform changes downstream from a distributive pattern to a contributory pattern. In others, channels terminate at an axial fluvial system, at the coast, in eolian dune fields, playa lakes, permanent lakes, or wetlands. Large DFSs and their catchments are developed in all climatic regimes, including drylands, tropical, subtropical, continental, and polar climates. Large DFSs occur in all tectonic settings, including extensional, compressional, strike-slip, and cratonic tectonic regimes. General trends and relationships between the different studied parameters can be observed, leading to a broad understanding of the main controls on large DFS development. All of the planform types occur in all tectonic settings and all climate zones. Braided planforms dominate all tectonic settings, but particularly compressional regimes. High-gradient braided systems tend to be associated with areas of high relief and are well developed in dryland climates where discharge is inferred to be intermittent in comparison to tropical climates. Large DFSs with sinuous planforms do occur in dryland climates but tend to predominate in wetter, more tropical climates where discharge is more constant and the fluvial systems can distribute bedload more efficiently. Sinuous systems also tend to have significantly lower gradients than braided systems. Although these general observations can be made, there are significant variations from these trends, which are inferred to be controlled by variations in (1) discharge related to climate and (2) sediment supply, which is a function of climate, catchment size, catchment lithology, and catchment relief. Large DFS length is controlled by the available horizontal accommodation space, which in turn is strongly related to tectonic setting. The longest DFSs occur in peripheral foreland basins and cratonic settings where lateral systems can develop across an extensive basinwards slope. Extensional, strike-slip, and piggy-back basins are narrower and have much more limited horizontal accommodation space. Consequently DFSs developed in these settings are shorter, with radii often less than 30 km. DFSs dominate in aggradational settings such as actively subsiding sedimentary basins and therefore form a significant proportion of alluvial sedimentary successions preserved in the rock record.

@article{doi102110jsr2010016,
    author = "Hartley, Adrian J. and Weissmann, Gary S. and Nichols, Gary and Warwick, Gail L.",
    title = "Large Distributive Fluvial Systems: Characteristics, Distribution, and Controls on Development",
    year = "2010",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract An analysis of remotely sensed imagery reveals that fluvial planform geometries within aggrading continental areas are dominated by distributive fluvial systems (DFSs). We documented the gradient, length, apex location, planform, termination type, and tectonic and climatic setting of 415 examples of fluvial systems which in planform display a radial, distributive channel pattern and have an apex–toe distance \> 30 km (large DFSs). The longest of these DFSs is 704 km in length, with the majority (72\%) ranging between 30 and 100 km in length. Gradients on individual systems range from 0.00003 (0.0018°) to 0.02656 (1.5°). Six planform types are recognized, those with: (1) a single braided channel that bifurcates downstream into braided and/or straight channels, (2) a single dominant braided channel, (3) a single dominant braided channel which becomes sinuous downstream often bifurcating, (4) a single dominant sinuous channel, (5) a single sinuous channel that bifurcates downstream into smaller sinuous channels, and (6) multiple sinuous channels. Of the studied examples 58\% occur within exorheic basins and 42\% in endorheic basins, with seven different termination types recognized. In many examples, channel planform changes downstream from a distributive pattern to a contributory pattern. In others, channels terminate at an axial fluvial system, at the coast, in eolian dune fields, playa lakes, permanent lakes, or wetlands. Large DFSs and their catchments are developed in all climatic regimes, including drylands, tropical, subtropical, continental, and polar climates. Large DFSs occur in all tectonic settings, including extensional, compressional, strike-slip, and cratonic tectonic regimes. General trends and relationships between the different studied parameters can be observed, leading to a broad understanding of the main controls on large DFS development. All of the planform types occur in all tectonic settings and all climate zones. Braided planforms dominate all tectonic settings, but particularly compressional regimes. High-gradient braided systems tend to be associated with areas of high relief and are well developed in dryland climates where discharge is inferred to be intermittent in comparison to tropical climates. Large DFSs with sinuous planforms do occur in dryland climates but tend to predominate in wetter, more tropical climates where discharge is more constant and the fluvial systems can distribute bedload more efficiently. Sinuous systems also tend to have significantly lower gradients than braided systems. Although these general observations can be made, there are significant variations from these trends, which are inferred to be controlled by variations in (1) discharge related to climate and (2) sediment supply, which is a function of climate, catchment size, catchment lithology, and catchment relief. Large DFS length is controlled by the available horizontal accommodation space, which in turn is strongly related to tectonic setting. The longest DFSs occur in peripheral foreland basins and cratonic settings where lateral systems can develop across an extensive basinwards slope. Extensional, strike-slip, and piggy-back basins are narrower and have much more limited horizontal accommodation space. Consequently DFSs developed in these settings are shorter, with radii often less than 30 km. DFSs dominate in aggradational settings such as actively subsiding sedimentary basins and therefore form a significant proportion of alluvial sedimentary successions preserved in the rock record.",
    url = "https://doi.org/10.2110/jsr.2010.016",
    doi = "10.2110/jsr.2010.016",
    openalex = "W2101236769",
    references = "doi102110jsr2006060"
}

Groundwater is an important resource for agricultural and municipal uses in the Mississippi embayment. Arkansas ranks first in the Nation for rice and third for cotton production, with both crops dependent on groundwater as a major source of irrigation requirements. Multiple municipalities rely on the groundwater resources to provide water for industrial and public use, which includes the city of Memphis, Tennessee. The demand for the groundwater resource has resulted in groundwater availability issues in the Mississippi embayment including: (1) declining groundwater levels of 50 feet or more in the Mississippi River Valley alluvial aquifer in parts of eastern Arkansas from agricultural pumping, (2) declining groundwater levels of over 360 feet over the last 90 years in the confined middle Claiborne aquifer in southern Arkansas and northern Louisiana from municipal pumping, and (3) litigation between the State of Mississippi and a Memphis water utility over water rights in the middle Claiborne aquifer. To provide information to stakeholders addressing the groundwater-availability issues, the U.S. Geological Survey Groundwater Resources Program supported a detailed assessment of groundwater availability through the Mississippi Embayment Regional Aquifer Study (MERAS). This assessment included (1) an evaluation of how these resources have changed over time through the use of groundwater budgets, (2) development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends, and (3) application of statistical tools to evaluate the importance of individual observations within a groundwater-monitoring network. An estimated 12 million acre-feet per year (11 billion gallons per day) of groundwater was pumped in 2005 from aquifers in the Mississippi embayment. Irrigation constitutes the largest groundwater use, accounting for approximately 10 million acre-feet per year (9 billion gallons per day) in 2000 from the Mississippi River Valley alluvial aquifer in Arkansas, Louisiana, Mississippi, and Missouri, and to a lesser extent in Illinois, Kentucky, and Tennessee. Predevelopment groundwater flow is represented in the MERAS model as a steady-state stress period, assumed to be prior to 1870. The simulated groundwater-flow budget indicates the largest predevelopment inflow to the system is net recharge to the alluvial aquifer. This inflow is balanced by outflow to gaining streams. Overall, water enters as net recharge to the alluvial aquifer or through outcrop areas of the various hydrogeologic units. Away from the outcrop areas, groundwater flow in the deeper formations is primarily upward into overlying units, ultimately discharging to streams through the alluvial aquifer. Total net recharge and discharge (sum of inflows or outflows) for the model ranged from about 0.66 million acre-feet per year during predevelopment to 20.16 million acre-feet per year by the end of the simulation (final simulated irrigation period in summer of 2006). This change in the model budget reflects increases in withdrawals compared to predevelopment conditions. Cumulative storage within aquifers simulated in the MERAS model indicates overall depletion of 140 million acre-feet (equivalent to 2.8 feet of water covering the entire study area). Postdevelopment inflow to the system is still through net recharge to the alluvial aquifer and the outcrop areas of the several hydrogeologic units, however, the flow between each unit is no longer upward to the alluvial aquifer. Groundwater flow during the summer of 2006 was primarily downward to offset demand from pumping. Early in the model simulation (1870-1920s), the primary components of the water budget were simulated as outflow from stream leakage and inflow from net recharge. As pumpage increased through time, water that would otherwise flow to streams reversed, and net stream leakage became an inflow to the system. The largest reversals began in the mid-1980s, but indications of the reversal began in the early 1960s with a trend in loss of streamflow leakage coupled with the first consistent inflow from storage. While groundwater pumped out of the alluvial aquifer was derived primarily from storage, pumpage out of the middle Claiborne aquifer was derived primarily from other aquifers (up to 15 percent from the alluvial aquifer), followed by flow from storage and net recharge. The potential consequences of climate change have been identified as a major concern facing the sustainability of the Nation's groundwater resources. To address this concern, two climate simulations were developed through the use of the MERAS model by extending the simulation period by 30 years to the year 2038 using extrapolated precipitation based on frequency analysis of historic climate cycles. There is little difference between the dry and wet scenarios in terms of percent water-level change. Both scenarios resulted in 14.6 to 13.9 percent of the area containing more than 100 feet of decline, 14.5 to 13.8 percent containing between 75 and 100 feet of decline, and 15.8 to 15.7 percent containing 51 to 75 feet of decline in the alluvial aquifer. The middle Claiborne aquifer water-level changes also were similar between the two scenarios. These scenarios indicate that even with a 25-percent increase in precipitation from that of the dry scenario, there is little difference in the resultant water levels. This is in large part because of the magnitude of differences between changes in net recharge and changes in pumping. When compared to the volume of water pumped out of the system, the effect of this change in net recharge is negligible. The groundwater-level monitoring network used to construct the 2007 middle Claiborne aquifer potentiometric surface was used as an example case to demonstrate statistical technique and to evaluate the importance of individual groundwater-level observations. To calculate the importance of each water-level observation to a prediction, predictions were specified as water-level altitudes near the end of the dry scenario simulation. These predictions were located near the center of cones of depression. Many of the observations that have a high importance are in close proximity to stressed areas of the aquifer.

@article{doi103133pp1785,
    author = "Clark, Brian R. and Hart, Rheannon M. and Gurdak, Jason J.",
    title = "Groundwater availability of the Mississippi embayment",
    year = "2011",
    journal = "USGS professional paper",
    abstract = "Groundwater is an important resource for agricultural and municipal uses in the Mississippi embayment. Arkansas ranks first in the Nation for rice and third for cotton production, with both crops dependent on groundwater as a major source of irrigation requirements. Multiple municipalities rely on the groundwater resources to provide water for industrial and public use, which includes the city of Memphis, Tennessee. The demand for the groundwater resource has resulted in groundwater availability issues in the Mississippi embayment including: (1) declining groundwater levels of 50 feet or more in the Mississippi River Valley alluvial aquifer in parts of eastern Arkansas from agricultural pumping, (2) declining groundwater levels of over 360 feet over the last 90 years in the confined middle Claiborne aquifer in southern Arkansas and northern Louisiana from municipal pumping, and (3) litigation between the State of Mississippi and a Memphis water utility over water rights in the middle Claiborne aquifer. To provide information to stakeholders addressing the groundwater-availability issues, the U.S. Geological Survey Groundwater Resources Program supported a detailed assessment of groundwater availability through the Mississippi Embayment Regional Aquifer Study (MERAS). This assessment included (1) an evaluation of how these resources have changed over time through the use of groundwater budgets, (2) development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends, and (3) application of statistical tools to evaluate the importance of individual observations within a groundwater-monitoring network. An estimated 12 million acre-feet per year (11 billion gallons per day) of groundwater was pumped in 2005 from aquifers in the Mississippi embayment. Irrigation constitutes the largest groundwater use, accounting for approximately 10 million acre-feet per year (9 billion gallons per day) in 2000 from the Mississippi River Valley alluvial aquifer in Arkansas, Louisiana, Mississippi, and Missouri, and to a lesser extent in Illinois, Kentucky, and Tennessee. Predevelopment groundwater flow is represented in the MERAS model as a steady-state stress period, assumed to be prior to 1870. The simulated groundwater-flow budget indicates the largest predevelopment inflow to the system is net recharge to the alluvial aquifer. This inflow is balanced by outflow to gaining streams. Overall, water enters as net recharge to the alluvial aquifer or through outcrop areas of the various hydrogeologic units. Away from the outcrop areas, groundwater flow in the deeper formations is primarily upward into overlying units, ultimately discharging to streams through the alluvial aquifer. Total net recharge and discharge (sum of inflows or outflows) for the model ranged from about 0.66 million acre-feet per year during predevelopment to 20.16 million acre-feet per year by the end of the simulation (final simulated irrigation period in summer of 2006). This change in the model budget reflects increases in withdrawals compared to predevelopment conditions. Cumulative storage within aquifers simulated in the MERAS model indicates overall depletion of 140 million acre-feet (equivalent to 2.8 feet of water covering the entire study area). Postdevelopment inflow to the system is still through net recharge to the alluvial aquifer and the outcrop areas of the several hydrogeologic units, however, the flow between each unit is no longer upward to the alluvial aquifer. Groundwater flow during the summer of 2006 was primarily downward to offset demand from pumping. Early in the model simulation (1870-1920s), the primary components of the water budget were simulated as outflow from stream leakage and inflow from net recharge. As pumpage increased through time, water that would otherwise flow to streams reversed, and net stream leakage became an inflow to the system. The largest reversals began in the mid-1980s, but indications of the reversal began in the early 1960s with a trend in loss of streamflow leakage coupled with the first consistent inflow from storage. While groundwater pumped out of the alluvial aquifer was derived primarily from storage, pumpage out of the middle Claiborne aquifer was derived primarily from other aquifers (up to 15 percent from the alluvial aquifer), followed by flow from storage and net recharge. The potential consequences of climate change have been identified as a major concern facing the sustainability of the Nation's groundwater resources. To address this concern, two climate simulations were developed through the use of the MERAS model by extending the simulation period by 30 years to the year 2038 using extrapolated precipitation based on frequency analysis of historic climate cycles. There is little difference between the dry and wet scenarios in terms of percent water-level change. Both scenarios resulted in 14.6 to 13.9 percent of the area containing more than 100 feet of decline, 14.5 to 13.8 percent containing between 75 and 100 feet of decline, and 15.8 to 15.7 percent containing 51 to 75 feet of decline in the alluvial aquifer. The middle Claiborne aquifer water-level changes also were similar between the two scenarios. These scenarios indicate that even with a 25-percent increase in precipitation from that of the dry scenario, there is little difference in the resultant water levels. This is in large part because of the magnitude of differences between changes in net recharge and changes in pumping. When compared to the volume of water pumped out of the system, the effect of this change in net recharge is negligible. The groundwater-level monitoring network used to construct the 2007 middle Claiborne aquifer potentiometric surface was used as an example case to demonstrate statistical technique and to evaluate the importance of individual groundwater-level observations. To calculate the importance of each water-level observation to a prediction, predictions were specified as water-level altitudes near the end of the dry scenario simulation. These predictions were located near the center of cones of depression. Many of the observations that have a high importance are in close proximity to stressed areas of the aquifer.",
    url = "https://doi.org/10.3133/pp1785",
    doi = "10.3133/pp1785",
    openalex = "W1564578302"
}

Abstract Modern fluvial meander plains exhibit complex planform transformations in response to meander‐bend expansion, downstream migration and rotation. These transformations exert a fundamental control on lithology and reservoir properties, yet their stratigraphic record has been poorly evaluated in ancient examples due to the lack of extensive three‐dimensional exposures. Here, a unique exhumed meander plain exposed to the north of Scarborough (Yorkshire, UK) is analysed in terms of architecture and morphodynamics, with the aim of developing a comprehensive model of facies distribution. The studied outcrop comprises tidal platforms and adjacent cliffs, where the depositional architecture of un‐tilted deposits was assessed on planform and vertical sections, respectively. In its broader perspective, this study demonstrates the potential of architectural mapping of extensive planform exposures for the reconstruction of ancient fluvial morphodynamics. The studied exhumed meander plain is part of the Scalby Formation of the Ravenscar Group, and originally drained small coastal incised valleys within the Jurassic Cleveland Basin. The meander plain is subdivided into two storeys that contain in‐channel and overbank architectural elements. In‐channel elements comprise expansional and downstream‐migrating point bars, point‐bar tails and channel fills. Overbank elements comprise crevasse complexes, levées, floodplain fines and lake fills. The evolution of the point bars played a significant role in dictating preserved facies distributions, with high flood‐stage nucleation and accretion of meander scrolls later reworked during waning flood‐stages. At a larger scale, meander belt morphodynamics were also a function of valley confinement and contrasts in substrate erodibility. Progressive valley infilling decreased the valley confinement, promoting the upward transition from prevalently downstream migrating to expansional meander belts, a transition associated with enhanced preservation of overbank elements. Strikingly similar relations between valley confinement, meander‐bend transformations and overbank preservation are observed in small modern meandering streams such as the Beaver River of the Canadian prairies and the Powder River of Montana (USA).

@article{doi101111sed12122,
    author = "Ielpi, Alessandro and Ghinassi, Massimiliano",
    title = "Planform architecture, stratigraphic signature and morphodynamics of an exhumed Jurassic meander plain (Scalby Formation, Yorkshire, UK)",
    year = "2014",
    journal = "Sedimentology",
    abstract = "Abstract Modern fluvial meander plains exhibit complex planform transformations in response to meander‐bend expansion, downstream migration and rotation. These transformations exert a fundamental control on lithology and reservoir properties, yet their stratigraphic record has been poorly evaluated in ancient examples due to the lack of extensive three‐dimensional exposures. Here, a unique exhumed meander plain exposed to the north of Scarborough (Yorkshire, UK) is analysed in terms of architecture and morphodynamics, with the aim of developing a comprehensive model of facies distribution. The studied outcrop comprises tidal platforms and adjacent cliffs, where the depositional architecture of un‐tilted deposits was assessed on planform and vertical sections, respectively. In its broader perspective, this study demonstrates the potential of architectural mapping of extensive planform exposures for the reconstruction of ancient fluvial morphodynamics. The studied exhumed meander plain is part of the Scalby Formation of the Ravenscar Group, and originally drained small coastal incised valleys within the Jurassic Cleveland Basin. The meander plain is subdivided into two storeys that contain in‐channel and overbank architectural elements. In‐channel elements comprise expansional and downstream‐migrating point bars, point‐bar tails and channel fills. Overbank elements comprise crevasse complexes, levées, floodplain fines and lake fills. The evolution of the point bars played a significant role in dictating preserved facies distributions, with high flood‐stage nucleation and accretion of meander scrolls later reworked during waning flood‐stages. At a larger scale, meander belt morphodynamics were also a function of valley confinement and contrasts in substrate erodibility. Progressive valley infilling decreased the valley confinement, promoting the upward transition from prevalently downstream migrating to expansional meander belts, a transition associated with enhanced preservation of overbank elements. Strikingly similar relations between valley confinement, meander‐bend transformations and overbank preservation are observed in small modern meandering streams such as the Beaver River of the Canadian prairies and the Powder River of Montana (USA).",
    url = "https://doi.org/10.1111/sed.12122",
    doi = "10.1111/sed.12122",
    openalex = "W2132242758",
    references = "doi101016s0031018200002121, doi101016s003707380100118x, doi1010292010jf001838, doi1023071796493"
}

@article{doi104233uuid0dac02b570044aa499aa237adadfab1f,
    author = "Li, J.",
    title = "Terminal Fluvial Systems in a Semi-arid Endorheic Basin, Salar de Uyuni (Bolivia)",
    year = "2014",
    publisher = "Delft University of Technology",
    url = "https://www.semanticscholar.org/paper/6af7bd8ce073dcd0086399762f688a36d3795e25",
    doi = "10.4233/UUID:0DAC02B5-7004-4AA4-99AA-237ADADFAB1F",
    is_oa = "true",
    semanticscholar_citation_count = "10",
    semanticscholar_id = "6af7bd8ce073dcd0086399762f688a36d3795e25"
}

ABSTRACT The Pantanal Basin is an active sedimentary basin in central-west Brazil that consists of a complex alluvial systems tract characterized by the interaction between different river systems developed in one of the largest wetlands in the world. The Paraguay River is the trunk river system that drains the water and part of the sediment load received from areas outside of the basin. Depositional styles vary considerably along the river profiles throughout the basin, with the development of entrenched meandering belts, anastomosing reaches, and floodplain ponds. Paleodrainage patterns are preserved on the surface of abandoned lobes of fluvial fans, which also exhibit many degradational channels. Here, we propose a novel classification scheme according to which the geomorphology, hydrological regime and sedimentary dynamics of these fluvial systems are determined by the geology and geomorphology of the source areas. In this way, the following systems are recognized and described: (I) the Paraguay trunk-river plains; (II) fluvial fans sourced by the tablelands catchment area; (III) fluvial fans sourced by lowlands; and (IV) fluvial interfans. We highlight the importance of considering the influences of source areas when interpreting contrasting styles of fluvial architectures in the rock record.

@article{doi10159023174889201520150014,
    author = "Assine, Mário Luís and Merino, Éder Renato and do Nascimento Pupim, Fabiano and de Azevedo Macedo, Hudson and Santos, Maurício G. M.",
    title = "The Quaternary alluvial systems tract of the Pantanal Basin, Brazil",
    year = "2015",
    journal = "Brazilian Journal of Geology",
    abstract = "ABSTRACT The Pantanal Basin is an active sedimentary basin in central-west Brazil that consists of a complex alluvial systems tract characterized by the interaction between different river systems developed in one of the largest wetlands in the world. The Paraguay River is the trunk river system that drains the water and part of the sediment load received from areas outside of the basin. Depositional styles vary considerably along the river profiles throughout the basin, with the development of entrenched meandering belts, anastomosing reaches, and floodplain ponds. Paleodrainage patterns are preserved on the surface of abandoned lobes of fluvial fans, which also exhibit many degradational channels. Here, we propose a novel classification scheme according to which the geomorphology, hydrological regime and sedimentary dynamics of these fluvial systems are determined by the geology and geomorphology of the source areas. In this way, the following systems are recognized and described: (I) the Paraguay trunk-river plains; (II) fluvial fans sourced by the tablelands catchment area; (III) fluvial fans sourced by lowlands; and (IV) fluvial interfans. We highlight the importance of considering the influences of source areas when interpreting contrasting styles of fluvial architectures in the rock record.",
    url = "https://doi.org/10.1590/2317-4889201520150014",
    doi = "10.1590/2317-4889201520150014",
    openalex = "W2282963414",
    references = "doi1010079783662032374, doi101007s000270060856z, doi101016jsedgeo200607004, doi101016s0012825200000143, doi101127archivhydrobiol13719961, doi101130g302421, doi101146annurevearth32101802120201, doi101306m26490, doi102110jsr2010016, doi105860choice411567"
}

@article{doi101016jearscirev201511001,
    author = "Bentley, S. and Blum, M. and Maloney, J. and Pond, L. and Paulsell, R.",
    title = "The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene",
    year = "2016",
    journal = "Earth-Science Reviews",
    url = "https://www.sciencedirect.com/science/article/am/pii/S0012825215300623",
    doi = "10.1016/J.EARSCIREV.2015.11.001",
    is_oa = "true",
    pages = "139-174",
    semanticscholar_citation_count = "187",
    semanticscholar_id = "7b0b1a91358a562f905850981bc439bf6ecf395a",
    volume = "153",
    references = "doi101016jearscirev201510014, doi101130ges009171, doi101146annurevearth042711105248, doi101146annurevmarine120709142856"
}

In this study, we document sedimentary characteristics of overbank flood deposits associated with the epic A.D. 2011 flood along the Lower Mississippi River (southern USA) and directly compare the findings to sedimentation from a comparable flood event in 1973, with the general purpose of understanding how extreme floods contribute to floodplain depositional patterns and accretion rates of embanked fluvial systems. The thicknesses of the 2011 flood deposits averaged 138 mm along natural levee crests, 9 mm on meander scrolls, and 3 mm in backswamps. These thicknesses are considerably less than those documented for the 1973 flood, sampled at the same locations. We contend that less sedimentation in 2011 occurred because the flood was not supplied with much upstream sediment from the Missouri River. Further, the 2011 sediments are coarser than in 1973, indicating that the higher 2011 flood levels were associated with more energetic overbank flows that flushed fine-grained sediments downstream within the narrow embanked floodplain corridor. The largest recorded flood in North American history is only marginally preserved in the embanked floodplain stratigraphy of the alluvial valley of Earth’s third largest fluvial system.

@article{doi101130g385461,
    author = "Heitmuller, Franklin T. and Hudson, P. and Kesel, R. H.",
    title = "Overbank sedimentation from the historic A.D. 2011 flood along the Lower Mississippi River, USA",
    year = "2017",
    journal = "Geology",
    abstract = "In this study, we document sedimentary characteristics of overbank flood deposits associated with the epic A.D. 2011 flood along the Lower Mississippi River (southern USA) and directly compare the findings to sedimentation from a comparable flood event in 1973, with the general purpose of understanding how extreme floods contribute to floodplain depositional patterns and accretion rates of embanked fluvial systems. The thicknesses of the 2011 flood deposits averaged 138 mm along natural levee crests, 9 mm on meander scrolls, and 3 mm in backswamps. These thicknesses are considerably less than those documented for the 1973 flood, sampled at the same locations. We contend that less sedimentation in 2011 occurred because the flood was not supplied with much upstream sediment from the Missouri River. Further, the 2011 sediments are coarser than in 1973, indicating that the higher 2011 flood levels were associated with more energetic overbank flows that flushed fine-grained sediments downstream within the narrow embanked floodplain corridor. The largest recorded flood in North American history is only marginally preserved in the embanked floodplain stratigraphy of the alluvial valley of Earth’s third largest fluvial system.",
    url = "https://www.semanticscholar.org/paper/1ee8fb3b283ef943485076e4ef086d392aaee02b",
    doi = "10.1130/G38546.1",
    is_oa = "true",
    number = "2",
    pages = "107-110",
    semanticscholar_citation_count = "29",
    semanticscholar_id = "1ee8fb3b283ef943485076e4ef086d392aaee02b",
    volume = "45"
}

Abstract The evolution of rivers in eroding landscapes plays a key role in determining landscape relief and modulating climate‐tectonic interactions. A common approach to quantifying river system evolution uses a one‐dimensional, detachment‐limited stream power equation. One potential drawback of this model is that it does not incorporate the effects of changes in channel width or the role of sediment transport dynamics. Here I present a new method for modeling the influence of channel width on river dynamics to explore how variable width and sediment transport impact river profile evolution. With this approach, vertical river erosion can operate based on any number of river erosion models, such as a simple shear stress model (e.g., detachment limited), sediment cover‐shear stress hybrid models, or mechanistic saltation‐abrasion models. I explore the sensitivity of these three models to increases in rock‐uplift rate (i.e., 2, 3, 5, 10, and 20× increase). Generally, the results show that incorporating channel width adjustment or sediment transport dynamics lowers the sensitivity of a river profile to rock‐uplift rate. For the sediment transport‐dependent models, the degree of sensitivity depends on whether the system is limited by bedrock exposure or erosion potential (i.e., detachment potential). The approach produces transient responses that reveal distinct patterns of width and slope, which may provide valuable insight into the limiting physical mechanisms of bedrock erosion in a region. The implications of the work are broad and include the potential to distinguish underlying erosion controls from field observations of width and slope as well as understanding climate‐tectonic interactions.

@article{doi1010292017jf004405,
    author = "Yanites, Brian J.",
    title = "The Dynamics of Channel Slope, Width, and Sediment in Actively Eroding Bedrock River Systems",
    year = "2018",
    journal = "Journal of Geophysical Research Earth Surface",
    abstract = "Abstract The evolution of rivers in eroding landscapes plays a key role in determining landscape relief and modulating climate‐tectonic interactions. A common approach to quantifying river system evolution uses a one‐dimensional, detachment‐limited stream power equation. One potential drawback of this model is that it does not incorporate the effects of changes in channel width or the role of sediment transport dynamics. Here I present a new method for modeling the influence of channel width on river dynamics to explore how variable width and sediment transport impact river profile evolution. With this approach, vertical river erosion can operate based on any number of river erosion models, such as a simple shear stress model (e.g., detachment limited), sediment cover‐shear stress hybrid models, or mechanistic saltation‐abrasion models. I explore the sensitivity of these three models to increases in rock‐uplift rate (i.e., 2, 3, 5, 10, and 20× increase). Generally, the results show that incorporating channel width adjustment or sediment transport dynamics lowers the sensitivity of a river profile to rock‐uplift rate. For the sediment transport‐dependent models, the degree of sensitivity depends on whether the system is limited by bedrock exposure or erosion potential (i.e., detachment potential). The approach produces transient responses that reveal distinct patterns of width and slope, which may provide valuable insight into the limiting physical mechanisms of bedrock erosion in a region. The implications of the work are broad and include the potential to distinguish underlying erosion controls from field observations of width and slope as well as understanding climate‐tectonic interactions.",
    url = "https://doi.org/10.1029/2017jf004405",
    doi = "10.1029/2017jf004405",
    openalex = "W2804934611",
    references = "doi101130g317161"
}

Abstract Alluvial and fluvial fans are the most widespread depositional landforms bordering the margins of long-lived highland regions and actively subsiding continental basins, across a broad spectrum of tectonic and climatic settings. Their significance is relevant not only to the local morphodynamics of mountain regions and proximal basinal sectors, but also to the long-term evolution of sediment-routing systems, affecting the propagation of stratigraphic signals of environmental change and the preservation potential of stratal successions over much larger spatial scales than those they occupy. Subaerial fan systems archive information on the palaeoclimate, local tectonic history and landscape response to various allogenic factors, although our ability to decipher such information is still limited. Early recognition of alluvial fans dates from the late nineteenth century, but a coordinated research community on these systems has been active only over the last few decades and the full relevance of fluvial fan systems to the geomorphology of present day continental basins and to the interpretation of ancient stratigraphic successions has been convincingly demonstrated only over the last decade. This introductory chapter summarizes advances in our knowledge of alluvial and fluvial fans, identifies potential new lines of future inquiry, and presents the contributions to this volume in the context of the current state of research.

@article{doi101144sp44016,
    author = "Ventra, Dario and Clarke, Lucy",
    title = "Geology and geomorphology of alluvial and fluvial fans: current progress and research perspectives",
    year = "2018",
    journal = "Geological Society London Special Publications",
    abstract = "Abstract Alluvial and fluvial fans are the most widespread depositional landforms bordering the margins of long-lived highland regions and actively subsiding continental basins, across a broad spectrum of tectonic and climatic settings. Their significance is relevant not only to the local morphodynamics of mountain regions and proximal basinal sectors, but also to the long-term evolution of sediment-routing systems, affecting the propagation of stratigraphic signals of environmental change and the preservation potential of stratal successions over much larger spatial scales than those they occupy. Subaerial fan systems archive information on the palaeoclimate, local tectonic history and landscape response to various allogenic factors, although our ability to decipher such information is still limited. Early recognition of alluvial fans dates from the late nineteenth century, but a coordinated research community on these systems has been active only over the last few decades and the full relevance of fluvial fan systems to the geomorphology of present day continental basins and to the interpretation of ancient stratigraphic successions has been convincingly demonstrated only over the last decade. This introductory chapter summarizes advances in our knowledge of alluvial and fluvial fans, identifies potential new lines of future inquiry, and presents the contributions to this volume in the context of the current state of research.",
    url = "https://doi.org/10.1144/sp440.16",
    doi = "10.1144/sp440.16",
    openalex = "W2800258702",
    references = "doi101016jgeomorph200904025, doi10159023174889201520150014"
}

To improve flood-frequency estimates at rural streams in Mississippi, annual exceedance probability flows at gaged streams and regional regression equations used to estimate annual exceedance probability flows for ungaged streams were developed by using current geospatial data, new analytical methods, and annual peak-flow data through the 2013 water year. The regional regression equations were derived from statistical analyses of peak-flow data and basin characteristics for 281 streamgages and incorporated a newly developed study-specific skew coefficient at streamgages located in five subregional watersheds (Middle Tennessee-Elk, Mobile-Tombigbee, Lower Mississippi-Big Black, Pearl, and Pascagoula) in Mississippi. Three flood regions-A, B, and C-were identified based on residuals from the regional regression analyses and contain sites with similar basin characteristics. Analysis was not conducted for the fourth flood region, the Mississippi Alluvial Plain, because of insufficient long-term streamflow data and poorly defined basin characteristics.

@article{doi103133sir20185148,
    author = "Anderson, Brandon T.",
    title = "Flood frequency of rural streams in Mississippi, 2013",
    year = "2018",
    journal = "Scientific investigations report",
    abstract = "To improve flood-frequency estimates at rural streams in Mississippi, annual exceedance probability flows at gaged streams and regional regression equations used to estimate annual exceedance probability flows for ungaged streams were developed by using current geospatial data, new analytical methods, and annual peak-flow data through the 2013 water year. The regional regression equations were derived from statistical analyses of peak-flow data and basin characteristics for 281 streamgages and incorporated a newly developed study-specific skew coefficient at streamgages located in five subregional watersheds (Middle Tennessee-Elk, Mobile-Tombigbee, Lower Mississippi-Big Black, Pearl, and Pascagoula) in Mississippi. Three flood regions-A, B, and C-were identified based on residuals from the regional regression analyses and contain sites with similar basin characteristics. Analysis was not conducted for the fourth flood region, the Mississippi Alluvial Plain, because of insufficient long-term streamflow data and poorly defined basin characteristics.",
    url = "https://doi.org/10.3133/sir20185148",
    doi = "10.3133/sir20185148",
    openalex = "W2901742639",
    references = "crossref1985floodflow, doi101002wrcr20392, doi101016s0099111215301002, doi10102997wr01640, doi10106140976316563, doi101061asce108406992007125492, doi103133cir1309, doi103133sir20065146, doi103133sir20105260, doi103133sir20185148, doi103133wri034180, doi103133wri914037"
}

Abstract The Mississippi River Valley Alluvial Aquifer ranks among the most overdrafted aquifers in the United States due to intensive irrigation. Concern over declining water levels has increased focus on understanding the sources of recharge. Numerous oxbow lakes overlie the aquifer that are often considered hydraulically disconnected from the groundwater system due to fine‐grained bottom sediments. In the current study, groundwater levels in and around a 445‐ha oxbow lake‐wetland in Mississippi were monitored for a 2‐year period that included an unusually long low‐water condition in the lake (>17 months), followed by a high‐water event lasting over 4 months before returning to earlier low‐water levels. The high‐water pulse (>4 m rise) provided a unique opportunity to track the impact in the underlying alluvial aquifer. During low‐water conditions, groundwater flowed westward beneath the lake. Following the lake rise, groundwater beneath and near the perimeter responded as quickly as the same day, with more delayed responses moving away from the lake. Within 2 months, a groundwater mound formed near the centre of the oxbow (>3 m increase), with a reversal in the local hydraulic gradient towards the east. Flow returned to a westward gradient when the lake level dropped back below 0.3 m. Analysis of precipitation and nearby river stage could not account for the observed behavior. Recharge to the aquifer is attributed to rising water levels spreading over point bar deposits and into the surrounding forested wetlands where preferential flow pathways are likely to exist due to buried and decomposing tree remains. An earlier study in the wetland demonstrated an increasing redox potential in isolated zones, consistent with the existence of preferential flow pathways through the bottom sediments (Lahiri & Davidson, 2020). Retaining high‐water levels in oxbow lakes could be a relatively low‐cost water management practice for enhancing aquifer recharge.

@article{doi101002hyp13680,
    author = "Gratzer, Michael C. and Davidson, Gregg R. and O’Reilly, Andrew M. and Rigby, James R.",
    title = "Groundwater recharge from an oxbow lake‐wetland system in the Mississippi Alluvial Plain",
    year = "2019",
    journal = "Hydrological Processes",
    abstract = "Abstract The Mississippi River Valley Alluvial Aquifer ranks among the most overdrafted aquifers in the United States due to intensive irrigation. Concern over declining water levels has increased focus on understanding the sources of recharge. Numerous oxbow lakes overlie the aquifer that are often considered hydraulically disconnected from the groundwater system due to fine‐grained bottom sediments. In the current study, groundwater levels in and around a 445‐ha oxbow lake‐wetland in Mississippi were monitored for a 2‐year period that included an unusually long low‐water condition in the lake (>17 months), followed by a high‐water event lasting over 4 months before returning to earlier low‐water levels. The high‐water pulse (>4 m rise) provided a unique opportunity to track the impact in the underlying alluvial aquifer. During low‐water conditions, groundwater flowed westward beneath the lake. Following the lake rise, groundwater beneath and near the perimeter responded as quickly as the same day, with more delayed responses moving away from the lake. Within 2 months, a groundwater mound formed near the centre of the oxbow (>3 m increase), with a reversal in the local hydraulic gradient towards the east. Flow returned to a westward gradient when the lake level dropped back below 0.3 m. Analysis of precipitation and nearby river stage could not account for the observed behavior. Recharge to the aquifer is attributed to rising water levels spreading over point bar deposits and into the surrounding forested wetlands where preferential flow pathways are likely to exist due to buried and decomposing tree remains. An earlier study in the wetland demonstrated an increasing redox potential in isolated zones, consistent with the existence of preferential flow pathways through the bottom sediments (Lahiri \& Davidson, 2020). Retaining high‐water levels in oxbow lakes could be a relatively low‐cost water management practice for enhancing aquifer recharge.",
    url = "https://doi.org/10.1002/hyp.13680",
    doi = "10.1002/hyp.13680",
    openalex = "W2994909602",
    references = "doi103133ha730f"
}

First posted September 12, 2019 For additional information, contact: Director, Nebraska Water Science CenterU.S. Geological Survey5231 South 19th StreetLincoln, NE 68512 A potentiometric surface map for spring 2016 was created for the Mississippi River Valley alluvial (MRVA) aquifer using selected available groundwater-altitude data from wells and surface-water-altitude data from streamgages. Most of the wells were measured annually or one time after installation, but some wells were measured more than one time or continually; streamgages are typically operated continuously. Personnel from the Arkansas Natural Resources Commission, Arkansas Department of Health, Arkansas Geological Survey, Illinois Department of Agriculture, Illinois State Water Survey, Louisiana Department of Natural Resources, Louisiana Department of Transportation and Development, Mississippi Department of Environmental Quality, Yazoo Mississippi Delta Joint Water Management District, U.S. Department of Agriculture–Natural Resources Conservation Service, and the U.S. Geological Survey (USGS) routinely collect groundwater data from wells screened in the MRVA aquifer. The USGS and the U.S. Army Corps of Engineers routinely collect data on river stage and discharge for the rivers overlying the MRVA aquifer.The potentiometric surface map for 2016 was created using existing data as part of the USGS Water Availability and Use Science Program to support investigations that characterize the MRVA aquifer. Sufficient groundwater-altitude data were available to create a potentiometric-surface map for spring 2016 for about 81 percent of the aquifer area. The potentiometric contours ranged from 10 to 340 feet. The regional direction of groundwater flow in the MRVA aquifer was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers. There are large depressions in the potentiometric surface of the MRVA aquifer in the lower half of the Cache region and in most of the Grand Prairie and Delta regions.

@article{doi103133sim3439,
    author = "McGuire, Virginia L. and Seanor, Ronald C. and Asquith, William H. and Kress, Wade H. and Strauch, Kellan R.",
    title = "Potentiometric surface of the Mississippi River Valley alluvial aquifer, spring 2016",
    year = "2019",
    journal = "Scientific investigations map",
    abstract = "First posted September 12, 2019 For additional information, contact: Director, Nebraska Water Science CenterU.S. Geological Survey5231 South 19th StreetLincoln, NE 68512 A potentiometric surface map for spring 2016 was created for the Mississippi River Valley alluvial (MRVA) aquifer using selected available groundwater-altitude data from wells and surface-water-altitude data from streamgages. Most of the wells were measured annually or one time after installation, but some wells were measured more than one time or continually; streamgages are typically operated continuously. Personnel from the Arkansas Natural Resources Commission, Arkansas Department of Health, Arkansas Geological Survey, Illinois Department of Agriculture, Illinois State Water Survey, Louisiana Department of Natural Resources, Louisiana Department of Transportation and Development, Mississippi Department of Environmental Quality, Yazoo Mississippi Delta Joint Water Management District, U.S. Department of Agriculture–Natural Resources Conservation Service, and the U.S. Geological Survey (USGS) routinely collect groundwater data from wells screened in the MRVA aquifer. The USGS and the U.S. Army Corps of Engineers routinely collect data on river stage and discharge for the rivers overlying the MRVA aquifer.The potentiometric surface map for 2016 was created using existing data as part of the USGS Water Availability and Use Science Program to support investigations that characterize the MRVA aquifer. Sufficient groundwater-altitude data were available to create a potentiometric-surface map for spring 2016 for about 81 percent of the aquifer area. The potentiometric contours ranged from 10 to 340 feet. The regional direction of groundwater flow in the MRVA aquifer was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers. There are large depressions in the potentiometric surface of the MRVA aquifer in the lower half of the Cache region and in most of the Grand Prairie and Delta regions.",
    url = "https://doi.org/10.3133/sim3439",
    doi = "10.3133/sim3439",
    openalex = "W2973126212",
    references = "crossref1978the, doi103133cir1279, doi103133pp1416b, doi103133pp1785, doi103133pp448e, doi103133pp708, doi103133sir20065128, doi103133sir20085098, doi103133twri04a3, doi103133wri864178, doi103133wri884028"
}

Abstract. Reconstructing sediment pathways in fluvial and deltaic systems beyond instrumental records is challenging due to a lack of suitable methods. Here we explore the potential of luminescence methods for such purposes, focusing on bleaching of the optically stimulated luminescence (OSL) signal of quartz sediments in a large fluviodeltaic system across time and space. We approach this by comparing residual doses of sand and silt from the modern Mississippi River channel with estimated residual doses of sand isolated from Late Holocene Mississippi Delta mouth bar and overbank deposits. Further insight is obtained from a comparison of burial ages of paired quartz sand and silt of Mississippi Delta overbank deposits. In contrast to some previous investigations, we find that the bleaching of the OSL signal is at least as likely for finer sediment as for coarser sediment of the meandering Mississippi River and its delta. We attribute this to the differences in light exposure related to transport mode (bedload vs. suspended load). In addition, we find an unexpected spatiotemporal pattern in OSL bleaching of mouth bar sand deposits. We suggest this may be caused by changes in upstream pathways of the meandering channel belt(s) within the alluvial valley or by distributary channel and coastal dynamics within the delta. Our study demonstrates that the degree of OSL signal bleaching of sand in a large delta can be highly time- and/or space-dependent. Silt is shown to be generally sufficiently bleached in both the modern Mississippi River and associated paleo-deposits regardless of age, and silt may therefore provide a viable option for obtaining OSL chronologies in megadeltas. Our work contributes to initiatives to use luminescence signals to fingerprint sediment pathways within river channel networks and their deltas and also helps inform luminescence dating approaches in fluviodeltaic environments.

@article{doi105194esurf77232019,
    author = "Chamberlain, E. and Wallinga, J.",
    title = "Seeking enlightenment of fluvial sediment pathways by optically stimulated luminescence signal bleaching of river sediments and deltaic deposits",
    year = "2019",
    journal = "Earth Surface Dynamics",
    abstract = "Abstract. Reconstructing sediment pathways in fluvial and deltaic systems beyond instrumental records is challenging due to a lack of suitable methods. Here we explore the potential of luminescence methods for such purposes, focusing on bleaching of the optically stimulated luminescence (OSL) signal of quartz sediments in a large fluviodeltaic system across time and space. We approach this by comparing residual doses of sand and silt from the modern Mississippi River channel with estimated residual doses of sand isolated from Late Holocene Mississippi Delta mouth bar and overbank deposits. Further insight is obtained from a comparison of burial ages of paired quartz sand and silt of Mississippi Delta overbank deposits. In contrast to some previous investigations, we find that the bleaching of the OSL signal is at least as likely for finer sediment as for coarser sediment of the meandering Mississippi River and its delta. We attribute this to the differences in light exposure related to transport mode (bedload vs. suspended load). In addition, we find an unexpected spatiotemporal pattern in OSL bleaching of mouth bar sand deposits. We suggest this may be caused by changes in upstream pathways of the meandering channel belt(s) within the alluvial valley or by distributary channel and coastal dynamics within the delta. Our study demonstrates that the degree of OSL signal bleaching of sand in a large delta can be highly time- and/or space-dependent. Silt is shown to be generally sufficiently bleached in both the modern Mississippi River and associated paleo-deposits regardless of age, and silt may therefore provide a viable option for obtaining OSL chronologies in megadeltas. Our work contributes to initiatives to use luminescence signals to fingerprint sediment pathways within river channel networks and their deltas and also helps inform luminescence dating approaches in fluviodeltaic environments.",
    url = "https://esurf.copernicus.org/articles/7/723/2019/esurf-7-723-2019.pdf",
    doi = "10.5194/ESURF-7-723-2019",
    is_oa = "true",
    number = "3",
    pages = "723-736",
    semanticscholar_citation_count = "31",
    semanticscholar_id = "38196989a463b2bff2ee3f46b419ae3d5349a0b5",
    volume = "7",
    references = "doi1010801556489420181458764"
}

Large-scale computational investigations of groundwater levels are proposed to accelerate science delivery through a workflow spanning database assembly, statistics, and information synthesis and packaging. A water-availability study of the Mississippi River alluvial plain, and particularly the Mississippi River Valley alluvial aquifer (MRVA), is ongoing. Software (visGWDBmrva) has been released as part of the study that demonstrates groundwater informatics for the aquifer. Considerable water-level data collected by multiple agencies over a seven-state area exist (18,903 wells; 287,272 measurements [April 22, 2019]). Data and metadata quality assurance methods, basic statistics, hydrograph visualization, outlier identification, hypothesis testing, and time-series modeling are described. Two approaches (generalized additive models [GAMs] and support vector machines [SVMs]) are used for data interpolation and extension to monthly water-level estimates. Numerical congruence between GAM and SVM estimates will be useful to limit inclusion of monthly estimates from subsequent science activities.

@article{doi101016jenvsoft2020104758,
    author = "Asquith, William H. and Seanor, Ronald C. and McGuire, Virginia L. and Kress, Wade H.",
    title = "Methods to quality assure, plot, summarize, interpolate, and extend groundwater-level information—examples for the Mississippi River Valley alluvial aquifer",
    year = "2020",
    journal = "Environmental Modelling \& Software",
    abstract = "Large-scale computational investigations of groundwater levels are proposed to accelerate science delivery through a workflow spanning database assembly, statistics, and information synthesis and packaging. A water-availability study of the Mississippi River alluvial plain, and particularly the Mississippi River Valley alluvial aquifer (MRVA), is ongoing. Software (visGWDBmrva) has been released as part of the study that demonstrates groundwater informatics for the aquifer. Considerable water-level data collected by multiple agencies over a seven-state area exist (18,903 wells; 287,272 measurements [April 22, 2019]). Data and metadata quality assurance methods, basic statistics, hydrograph visualization, outlier identification, hypothesis testing, and time-series modeling are described. Two approaches (generalized additive models [GAMs] and support vector machines [SVMs]) are used for data interpolation and extension to monthly water-level estimates. Numerical congruence between GAM and SVM estimates will be useful to limit inclusion of monthly estimates from subsequent science activities.",
    url = "https://doi.org/10.1016/j.envsoft.2020.104758",
    doi = "10.1016/j.envsoft.2020.104758",
    openalex = "W3039253616",
    references = "doi103133ha730f, doi103133sim3439"
}

Highlights Between 1950 and 2017, there was a 12-fold increase in irrigated area in Arkansas and a doubling in Louisiana. Groundwater provides over 90% of the irrigation water applied to the 4 Mha of cropland in the LMRB. Ongoing efforts to address aquifer declines have been multi-faceted and include those of producers, public (local, state, and federal) institutions, and private organizations. Irrigation water management innovations include precision grading, reduced-flood or no-flood rice irrigation, pump automation, computerized hole selection, flowmeter requirements, and permit-based water use limitations. Abstract. The Lower Mississippi River Basin (LMRB) is an agricultural region of national and international significance. The basin relies heavily on the Mississippi River Valley alluvial aquifer to provide over 90% of the irrigation water applied to over four million hectares of cropland, with Arkansas using approximately 70% of the water and Mississippi and Missouri using approximately 15% each. Surface methods predominate, especially furrow irrigation using plastic lay-flat tubing in corn, cotton, peanut, and soybean and flood methods in rice. Irrigation extent has steadily increased by approximately 2% per year, such that irrigation withdrawals, combined with the region’s geology, have led to considerable aquifer declines in portions of Arkansas and Mississippi. Attempts to address these declines have been multi-faceted and include innovations in crop management and source water management, and programs in water resources management. Crop management innovations are focused on soybean and rice production and include precision grading, reduced-flood or no-flood rice irrigation, pump automation, and computerized hole selection. Adoption of these practices remains heavily reliant on field demonstrations and extension outreach. Source water management innovations include on-farm reservoirs, managed aquifer recharge, and regional-scale river diversions. Due to the concerted efforts of producers participating in regional and state programs, progress has been made in making surface irrigation more efficient and less reliant on groundwater. However, aquifer decline remains a challenge to the LMRB’s economy, ecology, and culture. Keywords: Aquifer decline, Irrigation, Lower Mississippi River Basin, Mississippi River Valley alluvial aquifer, Surface water.

@article{doi1013031trans13970,
    author = "Reba, Michele L. and Massey, J.H.",
    title = "Surface Irrigation in the Lower Mississippi River Basin: Trends and Innovations",
    year = "2020",
    journal = "Transactions of the ASABE",
    abstract = "Highlights Between 1950 and 2017, there was a 12-fold increase in irrigated area in Arkansas and a doubling in Louisiana. Groundwater provides over 90\% of the irrigation water applied to the 4 Mha of cropland in the LMRB. Ongoing efforts to address aquifer declines have been multi-faceted and include those of producers, public (local, state, and federal) institutions, and private organizations. Irrigation water management innovations include precision grading, reduced-flood or no-flood rice irrigation, pump automation, computerized hole selection, flowmeter requirements, and permit-based water use limitations. Abstract. The Lower Mississippi River Basin (LMRB) is an agricultural region of national and international significance. The basin relies heavily on the Mississippi River Valley alluvial aquifer to provide over 90\% of the irrigation water applied to over four million hectares of cropland, with Arkansas using approximately 70\% of the water and Mississippi and Missouri using approximately 15\% each. Surface methods predominate, especially furrow irrigation using plastic lay-flat tubing in corn, cotton, peanut, and soybean and flood methods in rice. Irrigation extent has steadily increased by approximately 2\% per year, such that irrigation withdrawals, combined with the region’s geology, have led to considerable aquifer declines in portions of Arkansas and Mississippi. Attempts to address these declines have been multi-faceted and include innovations in crop management and source water management, and programs in water resources management. Crop management innovations are focused on soybean and rice production and include precision grading, reduced-flood or no-flood rice irrigation, pump automation, and computerized hole selection. Adoption of these practices remains heavily reliant on field demonstrations and extension outreach. Source water management innovations include on-farm reservoirs, managed aquifer recharge, and regional-scale river diversions. Due to the concerted efforts of producers participating in regional and state programs, progress has been made in making surface irrigation more efficient and less reliant on groundwater. However, aquifer decline remains a challenge to the LMRB’s economy, ecology, and culture. Keywords: Aquifer decline, Irrigation, Lower Mississippi River Basin, Mississippi River Valley alluvial aquifer, Surface water.",
    url = "https://doi.org/10.13031/trans.13970",
    doi = "10.13031/trans.13970",
    openalex = "W3084024484",
    references = "doi103133ha730f"
}

Abstract Meandering channels and valleys are dominant landscape features on Earth. Their morphology and remnants potentially indicate past base‐level fluctuations and changing regional slopes. The prevailing presence of meandering segments in low‐slope areas somewhat confuses the physically based relationships between slope and channel meandering. This relationship underlies a fundamental debate: do incised sinuous channels actively develop during steepening of a regional slope, or do they inherit the planform of a preexisting sinuous channel through vertical incision? This question was previously explored through reconstructed evolution of meandering rivers, numerical simulations, and controlled, scaled‐down laboratory experiments. Here, we study a rare, field‐scale set of a dozen adjacent perennial channels, evolving in recent decades in a homogeneous erodible substrate in response to the Dead Sea level fall (> 30 m over 40 years). These channels are fed by perennial springs and have no drainage basin or previous fluvial history; they initiated straight and transformed into incising meandering channels following the emergence of the preexisting lake bathymetry, which resulted in increased channel lengths and regional slopes at different rates for each channel. This field setting allows testing the impact of changing regional slope on the sinuosity of a stream in the following cases: (a) relatively long and low‐gradient shelf‐like margins, (b) a sharp increase in the basinward gradient at the shelf‐slope transition, and (c) gradually steepening slopes. Under a stable and low valley slope, the channels mainly incise vertically, inheriting a preexisting sinuous pattern. When the regional slope steepens, the channels start to meander, accompanying the vertical incision. The highest sinuosity evolved in the steepest channel, which also developed the deepest and widest valley. These results emphasize the amplifying impact of steepening regional slope on sinuosity. This holds when the flow is confined and chute cutoffs are scarce.

@article{doi101002esp5085,
    author = "Dente, Elad and Lensky‬‏, Nadav G. and Morin, Efrat and Enzel, Yehouda",
    title = "From straight to deeply incised meandering channels: Slope impact on sinuosity of confined streams",
    year = "2021",
    journal = "Earth Surface Processes and Landforms",
    abstract = "Abstract Meandering channels and valleys are dominant landscape features on Earth. Their morphology and remnants potentially indicate past base‐level fluctuations and changing regional slopes. The prevailing presence of meandering segments in low‐slope areas somewhat confuses the physically based relationships between slope and channel meandering. This relationship underlies a fundamental debate: do incised sinuous channels actively develop during steepening of a regional slope, or do they inherit the planform of a preexisting sinuous channel through vertical incision? This question was previously explored through reconstructed evolution of meandering rivers, numerical simulations, and controlled, scaled‐down laboratory experiments. Here, we study a rare, field‐scale set of a dozen adjacent perennial channels, evolving in recent decades in a homogeneous erodible substrate in response to the Dead Sea level fall (> 30 m over 40 years). These channels are fed by perennial springs and have no drainage basin or previous fluvial history; they initiated straight and transformed into incising meandering channels following the emergence of the preexisting lake bathymetry, which resulted in increased channel lengths and regional slopes at different rates for each channel. This field setting allows testing the impact of changing regional slope on the sinuosity of a stream in the following cases: (a) relatively long and low‐gradient shelf‐like margins, (b) a sharp increase in the basinward gradient at the shelf‐slope transition, and (c) gradually steepening slopes. Under a stable and low valley slope, the channels mainly incise vertically, inheriting a preexisting sinuous pattern. When the regional slope steepens, the channels start to meander, accompanying the vertical incision. The highest sinuosity evolved in the steepest channel, which also developed the deepest and widest valley. These results emphasize the amplifying impact of steepening regional slope on sinuosity. This holds when the flow is confined and chute cutoffs are scarce.",
    url = "https://doi.org/10.1002/esp.5085",
    doi = "10.1002/esp.5085",
    openalex = "W3126175814",
    references = "doi1010160341816294900019, doi101016jgeomorph200508023, doi101016jmargeo201105008, doi101016s0040195199000116, doi101017s0022112076000748, doi1010292010jg001585, doi101046j13653091200000008x, doi101086648221, doi101130001676061972831755esocp20co2, doi1011300016760620021141131nmofst20co2, moore1926origin, openalexw2270285851"
}

Rivers are dynamic landscape features which are often altered by human activity, making it difficult to disentangle human impact on geomorphic change from natural river dynamics. This study evaluated the human impact on river planform change within the context of short- and long-term river channel dynamics in the Himalayan Sutlej and Beas Rivers, by (i) systematically assessing river planform change over centennial, annual, seasonal and episodic timescales; (ii) connecting observed changes to human-environment drivers; and (iii) conceptualising these geomorphic changes in terms of timescale-dependent evolutionary trajectories (press, ramp, pulse). Landsat imagery was used to extract components of the post-monsoon active river channel (1989–2018), using the modified Normalized Differences Water Index to identify the wet river area, and visible red to determine active gravel bars. Findings were compared with a historical map to represent the pre-dam period (1847–1850) and with data on potential driving factors of change (discharge, climate and land cover). River planform characteristics changed significantly over all timescales, exhibiting strong spatiotemporal variation between and within both rivers. Dam construction likely caused channel narrowing and straightening at the centennial scale (press trajectory). In the Sutlej, this process has continued over the last 30 years, likely enforced by the cumulative effect of water abstraction and climatic changes (ramp trajectory). In the Beas, the pattern of change in river planform metrics was less pronounced over the same period and more variable along the length of the river, possibly linked to different dam operations that maintain a higher degree of flow variability and peak flows (press trajectory). High local erosion rates caused by aggregate mining (episodic) in the Sutlej were also observed (pulse trajectory). Expressed as evolutionary trajectories, the observed responses to human activity confirm the importance of legacy effects of human impact on river systems, and stress the dependency on spatial and temporal scales to determine trajectories of change. The multi-timescale assessment and conceptualisation provide insights into different dimensions of human impact on river planform change, which is pivotal to developing holistic management strategies.

@article{doi101016jgeomorph2021107659,
    author = "Vercruysse, Kim and Grabowski, Robert",
    title = "Human impact on river planform within the context of multi-timescale river channel dynamics in a Himalayan river system",
    year = "2021",
    journal = "Geomorphology",
    abstract = "Rivers are dynamic landscape features which are often altered by human activity, making it difficult to disentangle human impact on geomorphic change from natural river dynamics. This study evaluated the human impact on river planform change within the context of short- and long-term river channel dynamics in the Himalayan Sutlej and Beas Rivers, by (i) systematically assessing river planform change over centennial, annual, seasonal and episodic timescales; (ii) connecting observed changes to human-environment drivers; and (iii) conceptualising these geomorphic changes in terms of timescale-dependent evolutionary trajectories (press, ramp, pulse). Landsat imagery was used to extract components of the post-monsoon active river channel (1989–2018), using the modified Normalized Differences Water Index to identify the wet river area, and visible red to determine active gravel bars. Findings were compared with a historical map to represent the pre-dam period (1847–1850) and with data on potential driving factors of change (discharge, climate and land cover). River planform characteristics changed significantly over all timescales, exhibiting strong spatiotemporal variation between and within both rivers. Dam construction likely caused channel narrowing and straightening at the centennial scale (press trajectory). In the Sutlej, this process has continued over the last 30 years, likely enforced by the cumulative effect of water abstraction and climatic changes (ramp trajectory). In the Beas, the pattern of change in river planform metrics was less pronounced over the same period and more variable along the length of the river, possibly linked to different dam operations that maintain a higher degree of flow variability and peak flows (press trajectory). High local erosion rates caused by aggregate mining (episodic) in the Sutlej were also observed (pulse trajectory). Expressed as evolutionary trajectories, the observed responses to human activity confirm the importance of legacy effects of human impact on river systems, and stress the dependency on spatial and temporal scales to determine trajectories of change. The multi-timescale assessment and conceptualisation provide insights into different dimensions of human impact on river planform change, which is pivotal to developing holistic management strategies.",
    url = "https://doi.org/10.1016/j.geomorph.2021.107659",
    doi = "10.1016/j.geomorph.2021.107659",
    openalex = "W3130720190",
    references = "doi101016jgeomorph201810007"
}

Manganese (Mn) concentrations and the probability of arsenic (As) exceeding the drinking-water standard of 10 μg/L were predicted in the Mississippi River Valley alluvial aquifer (MRVA) using boosted regression trees (BRT). BRT, a type of ensemble-tree machine-learning model, were created using predictor variables that affect Mn and As distribution in groundwater. These variables included iron (Fe) concentrations and specific conductance predicted from previously developed BRT models, groundwater flux and age estimates from MODFLOW, and hydrologic characteristics. The models also included results from the first airborne geophysical survey conducted in the United States to target an entire aquifer system. Predictions of high Mn and As occurred where Fe was high. Predicted high Mn concentrations were correlated with fraction of young groundwater (less than 65 years) computed from MODFLOW results. High probabilities of As exceedance were predicted where groundwater was relatively old and airborne electromagnetic resistivity was high, typically proximal to streams. Two-variable partial-dependence plots and sensitivity analysis were used to provide insight into the factors controlling Mn and As distribution in groundwater. The maps of predicted Mn concentrations and As exceedance probabilities can be used to identify areas where these constituents may be high, and that could be targeted for further study. This paper shows that incorporation of a selected set of process-informed data, such as MODFLOW results and airborne geophysics, into a machine-learning model improves model interpretability. Incorporation of process-rich information into machine-learning models will likely be useful for addressing a wide range of problems of interest to groundwater hydrologists.

@article{doi101111gwat13164,
    author = "Knierim, Katherine J. and Kingsbury, James A. and Belitz, Kenneth and Stackelberg, Paul E. and Minsley, Burke J. and Rigby, James R.",
    title = "Mapped Predictions of Manganese and Arsenic in an Alluvial Aquifer Using Boosted Regression Trees",
    year = "2021",
    journal = "Ground Water",
    abstract = "Manganese (Mn) concentrations and the probability of arsenic (As) exceeding the drinking-water standard of 10 μg/L were predicted in the Mississippi River Valley alluvial aquifer (MRVA) using boosted regression trees (BRT). BRT, a type of ensemble-tree machine-learning model, were created using predictor variables that affect Mn and As distribution in groundwater. These variables included iron (Fe) concentrations and specific conductance predicted from previously developed BRT models, groundwater flux and age estimates from MODFLOW, and hydrologic characteristics. The models also included results from the first airborne geophysical survey conducted in the United States to target an entire aquifer system. Predictions of high Mn and As occurred where Fe was high. Predicted high Mn concentrations were correlated with fraction of young groundwater (less than 65 years) computed from MODFLOW results. High probabilities of As exceedance were predicted where groundwater was relatively old and airborne electromagnetic resistivity was high, typically proximal to streams. Two-variable partial-dependence plots and sensitivity analysis were used to provide insight into the factors controlling Mn and As distribution in groundwater. The maps of predicted Mn concentrations and As exceedance probabilities can be used to identify areas where these constituents may be high, and that could be targeted for further study. This paper shows that incorporation of a selected set of process-informed data, such as MODFLOW results and airborne geophysics, into a machine-learning model improves model interpretability. Incorporation of process-rich information into machine-learning models will likely be useful for addressing a wide range of problems of interest to groundwater hydrologists.",
    url = "https://doi.org/10.1111/gwat.13164",
    doi = "10.1111/gwat.13164",
    openalex = "W4200125209",
    references = "doi103133ha730f"
}

Annual exceedance probability flows at gaged locations and regional regression equations used to estimate annual exceedance probability flows at ungaged locations were developed by the U.S. Geological Survey, in cooperation with the Mississippi Department of Transportation, to improve floodfrequency estimates at rural streams in the alluvial plain of the lower Mississippi River. These estimates were developed using current geospatial data, analytical methods, and annual peak-flow data through September 2017 at 58 streamgages in the alluvial plain of the lower Mississippi River, including 9 in Mississippi, 35 in Arkansas, 4 in Missouri, and 10 in Louisiana. Annual exceedance probability flows presented in this report incorporate streamflow data through the 2017 water year, 32 additional years of record since the previous study in 1985 of flood magnitude and frequency in the Mississippi portion of the alluvial plain of the lower Mississippi River. Ranges for standard error of prediction, average variance of prediction, and pseudo-R 2 are 45-61 percent, 0.035-0.059 (log cubic feet per second) 2, and 90-94 percent, respectively.

@article{doi103133sir20215046,
    author = "Anderson, Brandon T.",
    title = "Magnitude and frequency of floods in the alluvial plain of the lower Mississippi River, 2017",
    year = "2021",
    journal = "Scientific investigations report",
    abstract = "Annual exceedance probability flows at gaged locations and regional regression equations used to estimate annual exceedance probability flows at ungaged locations were developed by the U.S. Geological Survey, in cooperation with the Mississippi Department of Transportation, to improve floodfrequency estimates at rural streams in the alluvial plain of the lower Mississippi River. These estimates were developed using current geospatial data, analytical methods, and annual peak-flow data through September 2017 at 58 streamgages in the alluvial plain of the lower Mississippi River, including 9 in Mississippi, 35 in Arkansas, 4 in Missouri, and 10 in Louisiana. Annual exceedance probability flows presented in this report incorporate streamflow data through the 2017 water year, 32 additional years of record since the previous study in 1985 of flood magnitude and frequency in the Mississippi portion of the alluvial plain of the lower Mississippi River. Ranges for standard error of prediction, average variance of prediction, and pseudo-R 2 are 45-61 percent, 0.035-0.059 (log cubic feet per second) 2, and 90-94 percent, respectively.",
    url = "https://doi.org/10.3133/sir20215046",
    doi = "10.3133/sir20215046",
    openalex = "W3168500612",
    references = "crossref1985floodflow, doi101002wrcr20392, doi10102997wr01640, doi101061asce108406992007125492, doi103133sir20065146, doi103133sir20105260, doi103133sir20145165, doi103133sir20165081, doi103133sir20215046, doi103133tm4a8, doi103133tm4b5, doi103133wri7352"
}

<p>&#160; &#160; &#160; The Inaou&#232;ne wadi is a river located in the northern region of Morocco. Its catchment area covers about 5124 km&#178; with an average altitude of 800 m. The tributaries drain the marly reliefs of the Prerif in the northern side, as well as its southern ones are crossing the liasic carbonate and the Paleozoic crystalline rocks of the last Middle Atlas foothills. This region is characterised by a semi-arid Mediterranean climate influenced by the ocean oscillations, the average annual rainfall records 600 mm with a very significant spatial and interannual irregularity.</p><p>Along the major part of its flow, the Inaou&#232;ne river has cut its bed between the Prerif and the Middle Atlas belts, by following the foreland corridor that separates them. From a pass (Touaher) that marks the corridor closing, the river valley widens from East to West, forming an alluvial plain with a maximum width of 5 km incised by a meandering and highly sinuous stream.</p><p>&#160; &#160; &#160; Alluvial deposits in this valley are more developed on the Atlas side than at the Prerif foot; At least five levels representing the vestiges of the Lower and Middle Pleistocene terraces are present in the landscape.</p><p>More recent deposits occupy the valley floor, they constitute a more homogeneous surface showing low terraces abrupts and lateral limits between different sedimentary units. These alluvial deposits correspond to the terminal Pleistocene, middle and upper Holocene epoch. About 30 samples of charcoal and TOC have been selected and analysed using the&#160; AMS 14C dating. Due to the scarcity of organic matter, some of the samples contained less than 0.1 mg of carbon and had to be analysed using the gas ion source (GIS) interface of the MICADAS (Haghipour et al., 2019; Wacker et al.,2013). 12 sections were described in the field and of which 8 sections were analysed regarding grain size, mineralogical composition, carbonate content as well as organic matter in soils and sediments.</p><p>&#160; &#160; &#160; The analysis results indicate that the late Pleistocene is characterised by a high fluvial activity reflected by the development of braided system river and so coarse material, while fine deposits of floodplains are more abundant during the Holocene.</p><p>&#8230;&#8230;...........</p><p><strong>Haghipour, N., Ausin, B., Usman, M. O., Ishikawa, N., Wacker, L., Welte, C., Ueda, K., and Eglinton, T. I., 2019, Compound-Specific Radiocarbon Analysis by Elemental Analyzer-Accelerator Mass Spectrometry: Precision and Limitations: Analytical Chemistry, v. 91, no. 3, p. 2042-2049.</strong></p><p><strong>Wacker, L., Fahrni, S., Hajdas, I., Molnar, M., Synal, H., Szidat, S., and Zhang, Y., 2013, A versatile gas interface for routine radiocarbon analysis with a gas ion source: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions With Materials and Atoms, v. 294, p. 315-319.</strong></p>

@article{doi105194egusphereegu2113533,
    author = "Lghamour, Mohammed and Karrat, L. and Picotti, V. and Hajdas, Irka and Haghipour, N. and Guidobaldi, Giulia and Heeb, Karin Wyss",
    title = "Alluvial deposits evolution in the Inaouene river valley (Morocco) during late Pleistocene and Holocene epoch.",
    year = "2021",
    abstract = "<p>\&\#160; \&\#160; \&\#160; The Inaou\&\#232;ne wadi is a river located in the northern region of Morocco. Its catchment area covers about 5124 km\&\#178; with an average altitude of 800 m. The tributaries drain the marly reliefs of the Prerif in the northern side, as well as its southern ones are crossing the liasic carbonate and the Paleozoic crystalline rocks of the last Middle Atlas foothills. This region is characterised by a semi-arid Mediterranean climate influenced by the ocean oscillations, the average annual rainfall records 600 mm with a very significant spatial and interannual irregularity.</p><p>Along the major part of its flow, the Inaou\&\#232;ne river has cut its bed between the Prerif and the Middle Atlas belts, by following the foreland corridor that separates them. From a pass (Touaher) that marks the corridor closing, the river valley widens from East to West, forming an alluvial plain with a maximum width of 5 km incised by a meandering and highly sinuous stream.</p><p>\&\#160; \&\#160; \&\#160; Alluvial deposits in this valley are more developed on the Atlas side than at the Prerif foot; At least five levels representing the vestiges of the Lower and Middle Pleistocene terraces are present in the landscape.</p><p>More recent deposits occupy the valley floor, they constitute a more homogeneous surface showing low terraces abrupts and lateral limits between different sedimentary units. These alluvial deposits correspond to the terminal Pleistocene, middle and upper Holocene epoch. About 30 samples of charcoal and TOC have been selected and analysed using the\&\#160; AMS 14C dating. Due to the scarcity of organic matter, some of the samples contained less than 0.1 mg of carbon and had to be analysed using the gas ion source (GIS) interface of the MICADAS (Haghipour et al., 2019; Wacker et al.,2013). 12 sections were described in the field and of which 8 sections were analysed regarding grain size, mineralogical composition, carbonate content as well as organic matter in soils and sediments.</p><p>\&\#160; \&\#160; \&\#160; The analysis results indicate that the late Pleistocene is characterised by a high fluvial activity reflected by the development of braided system river and so coarse material, while fine deposits of floodplains are more abundant during the Holocene.</p><p>\&\#8230;\&\#8230;...........</p><p><strong>Haghipour, N., Ausin, B., Usman, M. O., Ishikawa, N., Wacker, L., Welte, C., Ueda, K., and Eglinton, T. I., 2019, Compound-Specific Radiocarbon Analysis by Elemental Analyzer-Accelerator Mass Spectrometry: Precision and Limitations: Analytical Chemistry, v. 91, no. 3, p. 2042-2049.</strong></p><p><strong>Wacker, L., Fahrni, S., Hajdas, I., Molnar, M., Synal, H., Szidat, S., and Zhang, Y., 2013, A versatile gas interface for routine radiocarbon analysis with a gas ion source: Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions With Materials and Atoms, v. 294, p. 315-319.</strong></p>",
    url = "https://www.semanticscholar.org/paper/2573ab401a65d3e5631993b610c54651e6f86834",
    doi = "10.5194/EGUSPHERE-EGU21-13533",
    is_oa = "true",
    semanticscholar_id = "2573ab401a65d3e5631993b610c54651e6f86834"
}

@incollection{plinkbjörklund2021distributive,
    author = "Plink-Björklund, Piret",
    title = "Distributive Fluvial Systems: Fluvial and Alluvial Fans",
    year = "2021",
    booktitle = "Encyclopedia of Geology",
    url = "https://doi.org/10.1016/b978-0-08-102908-4.00015-1",
    doi = "10.1016/b978-0-08-102908-4.00015-1",
    openalex = "W4210492484",
    pages = "745-758",
    references = "doi1010160037073881900749, doi101016jsedgeo200607004, doi101086627271, doi1011300091761319950230365esoafa23co2, doi101130g302421, doi101177030913337700100202, doi101306d4267dde2b2611d78648000102c1865d, doi101306m31424, doi102110jsr2006026, doi102110jsr2010016"
}

The Mississippi River Valley alluvial aquifer (MRVAA) is one of the overexploited aquifers in the United States. Agriculture in Arkansas relies significantly on the MRVAA for irrigation, due to its accessibility and high yield. Increased irrigation demand since the early 1900s with continued expansion and inequitable recharge contributions resulted in groundwater decline. Overdraft of the MRVAA in Arkansas has resulted in the designation of critical groundwater areas. Managed aquifer recharge (MAR) methods intentionally replenish stressed groundwater resources. A MAR case study was conducted to determine whether infiltration basins, as repurposed borrow pits, could be used to enhance groundwater decline in critical groundwater areas of northeast Arkansas. This rehabilitation would be a practical solution to alleviate groundwater decline as well as economically feasible as land would not need to be taken out of production. In 2015, the Arkansas Department of Transportation contracted sand excavation of fallow land owned by a collaborating producer. This borrow pit would serve as a test case to measure infiltration rates into the MRVAA using nearby surface water as the recharge source. Initial soil core analyses revealed soil properties within the confining clay layer of red-brown clay and silty clay soils (0 to 3.7 m deep) with sand below. Excavation completed to a depth of ~6 m exposed the uppermost-unsaturated section of the alluvial aquifer, consisting of well-sorted medium grain size sand. The borrow pit floor was ~27 m above the existing water table, and it was hypothesized that this exposed unsaturated aquifer section would provide a natural filter and an avenue for increased water storage underground. Sediment samples were collected from the pit floor and sidewall pre- and postexperiment to characterize particle size, textural class, and organic matter. Submersible pressure transducers were installed within the pit and in a nearby irrigation well to monitor water level changes. Meteorological data were collected on-site to measure the water budget components of precipitation and evaporation. Water level declines and infiltration were evident throughout the experiment. An initial infiltration rate of 192 mm d −1 was measured in February of 2016 that decreased until March, with steady state rates of 4.43 to 136 mm d −1 that varied until June. An overall integrated infiltration rate of 36.4 mm d −1 was calculated from the water budget. Total subsurface storage increased by 9.3 ML from February to June of 2016, and a two-dimensional simulation predicted a maximum groundwater mounding of 2.6 m during the experiment. Additionally, 14 borrow pits that had not been repurposed were identified in the area using remote sensing. Results of this study demonstrate that a relatively inexpensive MAR strategy could be implemented using former borrow pits repurposed as infiltration basins to alleviate groundwater decline in a critical groundwater area of northeastern Arkansas.

@article{doi102489jswc202300021,
    author = "Leslie, Deborah L. and Reba, M.L. and Czarnecki, J.B.",
    title = "Managed aquifer recharge using a borrow pit in connection with the Mississippi River Valley alluvial aquifer in northeastern Arkansas",
    year = "2022",
    journal = "Journal of Soil and Water Conservation",
    abstract = "The Mississippi River Valley alluvial aquifer (MRVAA) is one of the overexploited aquifers in the United States. Agriculture in Arkansas relies significantly on the MRVAA for irrigation, due to its accessibility and high yield. Increased irrigation demand since the early 1900s with continued expansion and inequitable recharge contributions resulted in groundwater decline. Overdraft of the MRVAA in Arkansas has resulted in the designation of critical groundwater areas. Managed aquifer recharge (MAR) methods intentionally replenish stressed groundwater resources. A MAR case study was conducted to determine whether infiltration basins, as repurposed borrow pits, could be used to enhance groundwater decline in critical groundwater areas of northeast Arkansas. This rehabilitation would be a practical solution to alleviate groundwater decline as well as economically feasible as land would not need to be taken out of production. In 2015, the Arkansas Department of Transportation contracted sand excavation of fallow land owned by a collaborating producer. This borrow pit would serve as a test case to measure infiltration rates into the MRVAA using nearby surface water as the recharge source. Initial soil core analyses revealed soil properties within the confining clay layer of red-brown clay and silty clay soils (0 to 3.7 m deep) with sand below. Excavation completed to a depth of \textasciitilde 6 m exposed the uppermost-unsaturated section of the alluvial aquifer, consisting of well-sorted medium grain size sand. The borrow pit floor was \textasciitilde 27 m above the existing water table, and it was hypothesized that this exposed unsaturated aquifer section would provide a natural filter and an avenue for increased water storage underground. Sediment samples were collected from the pit floor and sidewall pre- and postexperiment to characterize particle size, textural class, and organic matter. Submersible pressure transducers were installed within the pit and in a nearby irrigation well to monitor water level changes. Meteorological data were collected on-site to measure the water budget components of precipitation and evaporation. Water level declines and infiltration were evident throughout the experiment. An initial infiltration rate of 192 mm d −1 was measured in February of 2016 that decreased until March, with steady state rates of 4.43 to 136 mm d −1 that varied until June. An overall integrated infiltration rate of 36.4 mm d −1 was calculated from the water budget. Total subsurface storage increased by 9.3 ML from February to June of 2016, and a two-dimensional simulation predicted a maximum groundwater mounding of 2.6 m during the experiment. Additionally, 14 borrow pits that had not been repurposed were identified in the area using remote sensing. Results of this study demonstrate that a relatively inexpensive MAR strategy could be implemented using former borrow pits repurposed as infiltration basins to alleviate groundwater decline in a critical groundwater area of northeastern Arkansas.",
    url = "https://doi.org/10.2489/jswc.2023.00021",
    doi = "10.2489/jswc.2023.00021",
    openalex = "W4311417120",
    references = "doi103133sim3439"
}

This article describes the opinions and perceptions of farmers on water management tools that conserve groundwater and on alternative sources of water for irrigation. The analysis is based on a survey of producers (N=466) across the Lower Mississippi River Basin (LMRB) areas of Arkansas, Louisiana, Mississippi, and Missouri. Summary statistics of practice usage across the region and for each state are presented. A Poisson count model is applied to the data to identify factors that influence the number of groundwater-conserving practices employed. The number of irrigated acres, years of farming, annual income level, perception of groundwater problems, and participation in conservation programs have statistically significant association with the number of practices employed. Years of farming experience is the only factor negatively associated with the number of practices employed, while participation in conservation programs has the largest magnitude effect on that number. These results provide evidence that sponsored conservation programs increase the number of conservation practices adopted by farmers. This insight is useful for producer collectives, policy makers, and program managers to design and target of conservation programs across the LMRB.

@article{doi103390agronomy12040894,
    author = "Quintana‐Ashwell, Nicolas E. and Gholson, Drew M. and Kaur, Gurpreet and Singh, Gurbir and Massey, J.H. and Krutz, L. Jason and Henry, Christopher G. and Cooke, Trey and Reba, Michele L. and Locke, Martin A.",
    title = "Irrigation Water Management Tools and Alternative Irrigation Sources Trends and Perceptions by Farmers from the Delta Regions of the Lower Mississippi River Basin in South Central USA",
    year = "2022",
    journal = "Agronomy",
    abstract = "This article describes the opinions and perceptions of farmers on water management tools that conserve groundwater and on alternative sources of water for irrigation. The analysis is based on a survey of producers (N=466) across the Lower Mississippi River Basin (LMRB) areas of Arkansas, Louisiana, Mississippi, and Missouri. Summary statistics of practice usage across the region and for each state are presented. A Poisson count model is applied to the data to identify factors that influence the number of groundwater-conserving practices employed. The number of irrigated acres, years of farming, annual income level, perception of groundwater problems, and participation in conservation programs have statistically significant association with the number of practices employed. Years of farming experience is the only factor negatively associated with the number of practices employed, while participation in conservation programs has the largest magnitude effect on that number. These results provide evidence that sponsored conservation programs increase the number of conservation practices adopted by farmers. This insight is useful for producer collectives, policy makers, and program managers to design and target of conservation programs across the LMRB.",
    url = "https://doi.org/10.3390/agronomy12040894",
    doi = "10.3390/agronomy12040894",
    openalex = "W4224304735",
    references = "doi103133sim3439"
}

@article{crossref2023river,
    title = "RIVER MEANDERS ON ALLUVIAL PLAINS AND HILLY TOPOGRAPHY",
    year = "2023",
    journal = "Journal of Environmental Science and Sustainable Development",
    url = "https://doi.org/10.7454/jessd.v6i1.1169",
    doi = "10.7454/jessd.v6i1.1169",
    number = "1",
    openalex = "W4385495394",
    volume = "6",
    references = "doi1010022013jf002997, doi1010079783319261942, doi101016jgeomorph200906028, doi101016jgeomorph201810007, doi101016jjseaes200603010, doi101017cbo9781107415324004, doi1010292010jf001838, doi101130g317161, doi10159023174889201520150014, doi1029118ipa62905g045"
}

The Southern Hills aquifer system (SHAS) in the Louisiana Capital Area Groundwater Conservation District (CAGCD), USA. The SHAS provides abundant groundwater for public and industrial supplies in the CAGCD. Groundwater depletion, saltwater intrusion, and land subsidence are potential concerns due to prolonged excessive groundwater withdrawals. This study develops a high-fidelity groundwater flow model utilizing a complex unstructured grid to investigate groundwater flow and storage responses to excessive groundwater withdrawals for the SHAS in the CAGCD. The groundwater model incorporates the Mississippi River alluvial aquifer down to the Miocene sands extending to depths around 1 km. Groundwater modeling results indicate large cones of depression in the Evangeline and Jasper formations in the Baton Rouge area due to prolonged groundwater withdrawals. Low-permeability faults are inferred by significant groundwater level difference across the faults. While local groundwater storage depletion in deeper aquifers is evident, overall estimated groundwater storage changes of the SHAS in the CAGCD are close to zero in the past two decades, indicating insignificant groundwater storage changes. This is attributed to dominant interactions between the major rivers and the shallower alluvial aquifer. In addition, the simulated groundwater storage changes exhibit patterns similar to those derived by the Gravity Recovery and Climate Experiment (GRACE) model that has been used in evaluation of groundwater depletion in many regional studies.

@article{doi101016jejrh2023101342,
    author = "Chen, Ye-Hong and Vahdat‐Aboueshagh, Hamid and Tsai, Frank T.‐C. and Dausman, Alyssa and Runge, Michael C.",
    title = "Unstructured-grid approach to develop high-fidelity groundwater model to understand groundwater flow and storage responses to excessive groundwater withdrawals in the Southern Hills aquifer system in southeastern Louisiana (USA)",
    year = "2023",
    journal = "Journal of Hydrology Regional Studies",
    abstract = "The Southern Hills aquifer system (SHAS) in the Louisiana Capital Area Groundwater Conservation District (CAGCD), USA. The SHAS provides abundant groundwater for public and industrial supplies in the CAGCD. Groundwater depletion, saltwater intrusion, and land subsidence are potential concerns due to prolonged excessive groundwater withdrawals. This study develops a high-fidelity groundwater flow model utilizing a complex unstructured grid to investigate groundwater flow and storage responses to excessive groundwater withdrawals for the SHAS in the CAGCD. The groundwater model incorporates the Mississippi River alluvial aquifer down to the Miocene sands extending to depths around 1 km. Groundwater modeling results indicate large cones of depression in the Evangeline and Jasper formations in the Baton Rouge area due to prolonged groundwater withdrawals. Low-permeability faults are inferred by significant groundwater level difference across the faults. While local groundwater storage depletion in deeper aquifers is evident, overall estimated groundwater storage changes of the SHAS in the CAGCD are close to zero in the past two decades, indicating insignificant groundwater storage changes. This is attributed to dominant interactions between the major rivers and the shallower alluvial aquifer. In addition, the simulated groundwater storage changes exhibit patterns similar to those derived by the Gravity Recovery and Climate Experiment (GRACE) model that has been used in evaluation of groundwater depletion in many regional studies.",
    url = "https://doi.org/10.1016/j.ejrh.2023.101342",
    doi = "10.1016/j.ejrh.2023.101342",
    openalex = "W4321507063",
    references = "doi103133ha730f"
}

Big Sunflower River Watershed (HUC 08030207) of the Lower Mississippi River Basin, United States Mississippi River Valley Alluvial Aquifer An on-farm water storage (OFWS) system is a structural best management practice (BMP) that captures irrigation and precipitation runoff from agricultural fields to be reused for irrigation. A geospatial inventory of OFWS systems was conducted in the Big Sunflower River Watershed (BSRW) to quantify surface water used for irrigation. Storage capacity and geographical extent of OFWS systems were compared to aquifer saturation and annual groundwater trends in the underlying Mississippi River Valley Alluvial Aquifer (MRVAA). Changes in surface water storage capacity were measured every two years from 2010 to 2020, and MRVAA trends were evaluated from 2000 to 2020. Since 2010, 794.5 ha of surface water storage was added to the BSRW. The lowest aquifer saturation (less than 60%) is in the middle of the watershed, but the area of 60%− 70% saturation is decreasing with the most OFWS systems installed in this area over the entire watershed. MRVAA groundwater levels declined from 2000 to 2015, but drawdowns decreased and water levels rose in observation wells from 2016 to 2020. This paper advances the understanding of how surface water use for irrigation - one of multiple human and natural factors that can affect groundwater levels - impacts MRVAA groundwater resources.

@article{doi101016jejrh2023101479,
    author = "Brock, Meredith L. and Tagert, Mary Love M. and Paz, Joel O. and Krutz, L. Jason",
    title = "Evaluation of on-farm water capture and groundwater decline in the Big Sunflower Watershed, Mississippi River Basin",
    year = "2023",
    journal = "Journal of Hydrology Regional Studies",
    abstract = "Big Sunflower River Watershed (HUC 08030207) of the Lower Mississippi River Basin, United States Mississippi River Valley Alluvial Aquifer An on-farm water storage (OFWS) system is a structural best management practice (BMP) that captures irrigation and precipitation runoff from agricultural fields to be reused for irrigation. A geospatial inventory of OFWS systems was conducted in the Big Sunflower River Watershed (BSRW) to quantify surface water used for irrigation. Storage capacity and geographical extent of OFWS systems were compared to aquifer saturation and annual groundwater trends in the underlying Mississippi River Valley Alluvial Aquifer (MRVAA). Changes in surface water storage capacity were measured every two years from 2010 to 2020, and MRVAA trends were evaluated from 2000 to 2020. Since 2010, 794.5 ha of surface water storage was added to the BSRW. The lowest aquifer saturation (less than 60\%) is in the middle of the watershed, but the area of 60\%− 70\% saturation is decreasing with the most OFWS systems installed in this area over the entire watershed. MRVAA groundwater levels declined from 2000 to 2015, but drawdowns decreased and water levels rose in observation wells from 2016 to 2020. This paper advances the understanding of how surface water use for irrigation - one of multiple human and natural factors that can affect groundwater levels - impacts MRVAA groundwater resources.",
    url = "https://doi.org/10.1016/j.ejrh.2023.101479",
    doi = "10.1016/j.ejrh.2023.101479",
    openalex = "W4384520957",
    references = "doi103133ha730f, doi103133sim3439"
}

Abstract River meanders entrenched into bedrock are found worldwide, and they are famously well represented in the Colorado Plateau of the southwestern U.S. Meandering of bedrock streams can eventually lead to cutting off canyon loops, and these abandoned “rincons” are locations with high preservation of fluvial deposits and landforms. We document and luminescence date the fluvial terraces in and around the Jackson Hole rincon along the Colorado River downstream of Moab, Utah. Results indicate cutoff and abandonment of the rincon at ~200 ka and also record the rapid and unsteady incision in this region over the past 300 ky. A convergence of conditions contributed to the cutoff of the rincon, including alluvial‐channel conditions at the onset of MIS 6 glacial‐climate, which provided channel‐bed cover and enhanced lateral erosion of weak strata. Also, a contemporaneous rock‐avalanche partially obstructed the paleochannel just downstream of the breach, potentially creating a backwater that further enabled a flood to avulse across the neck. Although other studies show that bedrock‐channel meandering and cutoff can generate unpaired strath terraces and short‐term increases in incision rates, these are not evident in the record at the Jackson Hole rincon. This novel case study leverages the high preservation potential within abandoned bedrock meanders to illuminate the processes and controls of rincon formation during landscape evolution.

@article{doi101002esp5886,
    author = "Pederson, Joel L. and Young, S. and Turley, Mike and Tanski, Natalie and Rittenour, Tammy M. and Harris, Ron",
    title = "The how, when, and why of an abandoned bedrock meander of the Colorado River, Utah (U.S.)",
    year = "2024",
    journal = "Earth Surface Processes and Landforms",
    abstract = "Abstract River meanders entrenched into bedrock are found worldwide, and they are famously well represented in the Colorado Plateau of the southwestern U.S. Meandering of bedrock streams can eventually lead to cutting off canyon loops, and these abandoned “rincons” are locations with high preservation of fluvial deposits and landforms. We document and luminescence date the fluvial terraces in and around the Jackson Hole rincon along the Colorado River downstream of Moab, Utah. Results indicate cutoff and abandonment of the rincon at \textasciitilde 200 ka and also record the rapid and unsteady incision in this region over the past 300 ky. A convergence of conditions contributed to the cutoff of the rincon, including alluvial‐channel conditions at the onset of MIS 6 glacial‐climate, which provided channel‐bed cover and enhanced lateral erosion of weak strata. Also, a contemporaneous rock‐avalanche partially obstructed the paleochannel just downstream of the breach, potentially creating a backwater that further enabled a flood to avulse across the neck. Although other studies show that bedrock‐channel meandering and cutoff can generate unpaired strath terraces and short‐term increases in incision rates, these are not evident in the record at the Jackson Hole rincon. This novel case study leverages the high preservation potential within abandoned bedrock meanders to illuminate the processes and controls of rincon formation during landscape evolution.",
    url = "https://doi.org/10.1002/esp.5886",
    doi = "10.1002/esp.5886",
    openalex = "W4399011140",
    references = "doi101002sici10969837199807237651aidesp89130co2v, doi101016jquageo201503012, doi101016jradmeas200806002, doi101016s1350448700000913, doi101016s1350448703000167, doi101016s135044879900253x, doi101029gm107p0237, doi101038313105a0, doi101111j15023885201200248x, doi1026034laatl2011443, openalexw2270285851"
}

Abstract Effective River system management is essential for conserving water resources, improving agricultural productivity, and sustaining ecological health. Remote sensing is crucial for evaluating and tracking several elements of river systems. The study explores the incorporation of remote sensing into Geographic Information Systems (GIS) and Artificial Intelligence (AI) to acquire a thorough comprehension of river dynamics and accurately record minor fluctuations in river conditions. The study demonstrates the utilization of satellite series such as Landsat, Sentinel to enhance monitoring and management methods through the analysis of high-resolution imagery and data. AI helps remote sensing by automating data processing, finding patterns, and making predictions about river conditions and trends. Machine learning techniques enhance the analytical capabilities of GIS and remote sensing data by accurately classifying land cover, predicting flood events, and evaluating water quality. The research highlights the novel approaches of utilizing remote sensing and GIS to tackle the issues related to data accessibility, analysis, and verification. The study also acknowledges specific constraints and difficulties, such as concerns over the accessibility of data, intricacies in analysis, and the processes involved in validation. The statement underscores the importance of ongoing research, technical progress, and collaboration among stakeholders to overcome these limitations and fully exploit the capabilities of remote sensing, artificial intelligence, and geographic information systems. An integrated approach is crucial for the development of successful policies and strategies that improve the resilience and sustainable management of river systems. This approach eventually promotes sustainable water resource practices and ecological preservation.

@article{doi101007s44288024000808,
    author = "Chatrabhuj and Meshram, Kundan and Mishra, Umank and Omar, Padam Jee",
    title = "Integration of remote sensing data and GIS technologies in river management system",
    year = "2024",
    journal = "Discover Geoscience",
    abstract = "Abstract Effective River system management is essential for conserving water resources, improving agricultural productivity, and sustaining ecological health. Remote sensing is crucial for evaluating and tracking several elements of river systems. The study explores the incorporation of remote sensing into Geographic Information Systems (GIS) and Artificial Intelligence (AI) to acquire a thorough comprehension of river dynamics and accurately record minor fluctuations in river conditions. The study demonstrates the utilization of satellite series such as Landsat, Sentinel to enhance monitoring and management methods through the analysis of high-resolution imagery and data. AI helps remote sensing by automating data processing, finding patterns, and making predictions about river conditions and trends. Machine learning techniques enhance the analytical capabilities of GIS and remote sensing data by accurately classifying land cover, predicting flood events, and evaluating water quality. The research highlights the novel approaches of utilizing remote sensing and GIS to tackle the issues related to data accessibility, analysis, and verification. The study also acknowledges specific constraints and difficulties, such as concerns over the accessibility of data, intricacies in analysis, and the processes involved in validation. The statement underscores the importance of ongoing research, technical progress, and collaboration among stakeholders to overcome these limitations and fully exploit the capabilities of remote sensing, artificial intelligence, and geographic information systems. An integrated approach is crucial for the development of successful policies and strategies that improve the resilience and sustainable management of river systems. This approach eventually promotes sustainable water resource practices and ecological preservation.",
    url = "https://doi.org/10.1007/s44288-024-00080-8",
    doi = "10.1007/s44288-024-00080-8",
    openalex = "W4403074048",
    references = "doi101016jgeomorph201810007"
}

• Quantified hydrologic connectivity for 1350 floodplain lakes within the historical floodplain of the Lower Mississippi River. • Identified a signature recurring pattern of connection for each lake, with specific months of connectivity followed by periods of disconnection, likely influenced by the interaction between lake characteristics and precipitation seasonality. • Provided a hydrologic connectivity analysis that can enhance floodplain management, offering frameworks for restoring connectivity and ecological integrity, and informing control measures for the spread of invasive species in agricultural floodplains. Hydrologic connectivity, the network of water pathways linking aquatic habitats, is vital for the exchange of organisms and abiotic materials between rivers and adjacent waterbodies. This study quantified hydrologic connectivity for 1,283 lakes in the Lower Mississippi River floodplain using satellite imagery, streamgauge data, and geospatial information. We aimed to assess connection frequency patterns between lakes and streams. Eight metrics describing temporal aspects of hydrologic connectivity were estimated, identifying trends by lake features and by stream size. Each lake exhibited a distinct pattern of connection, with specific months of connectivity followed by disconnection, likely influenced by lake characteristics and seasonal precipitation. Larger lakes showed increased connectivity, likely due to their surface area and volume, while smaller lakes were more prone to isolation, especially during dry periods. Lakes connected to large streams exhibited more prolonged and recurring connections, with less seasonal variation. In contrast, lakes near agricultural areas experienced reduced connectivity. However, local factors such as levees and artificial channels often disrupted these general trends. This hydrologic connectivity analysis can provide insight to support floodplain management, facilitate development of frameworks that restore connectivity, promote preservation of ecological integrity, and support management of invasive species spread in agricultural floodplains.

@article{doi101016jecolind2024112808,
    author = "Ahmad, Hafez and Miranda, L. E. and Dunn, Corey G. and Boudreau, Melanie R. and Colvin, Michael E.",
    title = "Connectivity patterns between floodplain lakes and neighboring streams in the historical floodplain of the Lower Mississippi River",
    year = "2024",
    journal = "Ecological Indicators",
    abstract = "• Quantified hydrologic connectivity for 1350 floodplain lakes within the historical floodplain of the Lower Mississippi River. • Identified a signature recurring pattern of connection for each lake, with specific months of connectivity followed by periods of disconnection, likely influenced by the interaction between lake characteristics and precipitation seasonality. • Provided a hydrologic connectivity analysis that can enhance floodplain management, offering frameworks for restoring connectivity and ecological integrity, and informing control measures for the spread of invasive species in agricultural floodplains. Hydrologic connectivity, the network of water pathways linking aquatic habitats, is vital for the exchange of organisms and abiotic materials between rivers and adjacent waterbodies. This study quantified hydrologic connectivity for 1,283 lakes in the Lower Mississippi River floodplain using satellite imagery, streamgauge data, and geospatial information. We aimed to assess connection frequency patterns between lakes and streams. Eight metrics describing temporal aspects of hydrologic connectivity were estimated, identifying trends by lake features and by stream size. Each lake exhibited a distinct pattern of connection, with specific months of connectivity followed by disconnection, likely influenced by lake characteristics and seasonal precipitation. Larger lakes showed increased connectivity, likely due to their surface area and volume, while smaller lakes were more prone to isolation, especially during dry periods. Lakes connected to large streams exhibited more prolonged and recurring connections, with less seasonal variation. In contrast, lakes near agricultural areas experienced reduced connectivity. However, local factors such as levees and artificial channels often disrupted these general trends. This hydrologic connectivity analysis can provide insight to support floodplain management, facilitate development of frameworks that restore connectivity, promote preservation of ecological integrity, and support management of invasive species spread in agricultural floodplains.",
    url = "https://doi.org/10.1016/j.ecolind.2024.112808",
    doi = "10.1016/j.ecolind.2024.112808",
    openalex = "W4404170353",
    references = "smith1996fluvial"
}

This study presents a systematic geochemical modeling methodology using a combination of data analysis techniques suitable for the predictive modeling of metal contamination processes in altered, heterogeneous fluvial sediment system as contamination receptor. Unlike conventional studies, this approach first characterizes the receptor fluvial sediments using (1) major ions (Fe, Al, K, Na, Ca, Mg, P), indicative of sediment mineralogy; and (2) standard soil parameters (pH, electrical conductivity, loss-on-ignition, CaCO 3 content, clay content), indicative of sediment chemistry, controlling metal behavior (e.g. adsorption, precipitation). In addition to unsupervised hierarchical cluster analysis and Q-mode (between-sample) principal component analysis, multivariate homogeneity tests such as the Mann−Whitney and Kruskal−Wallis median tests identify and verify distinct, geochemically homogeneous areas which, in this study, correspond to the contemporary riverbed sediments, the post-river regulation active alluvial plain, and to the old terrace developed under braided–meandering pre-river regulation conditions of the Drava River. The main geochemical processes in the receptor floodplain soils and sediments, characterized by associations of major ion concentrations and soil parameters, modeled with regression, partial correlation analysis and correlograms are: (1) calcareous geochemistry: Ca−Mg−pH−(CaCO 3 content), in the stream and alluvial plain sediments, defined by the regional geochemical background, (2) clay minerals (sericite–illite): K−Al−Fe−(Mg, clay content), in the river terrace soils, while (3) organic matter: loss-on-ignition−electrical conductivity−P, dominates the topsoil geochemistry in the floodplain. Second, the contamination source is modeled by geochemical fingerprinting using (1) metal associations, characteristic to the upstream mines of the Mississippi Valley-type Pb–Zn–Cd deposits such as the minerals wulfenite Pb(MoO 4), descloizite PbZn(VO 4)(OH), and pyromorphite Pb 5 (PO 4) 3 Cl, and (2) metal associations, characteristic to mafic–ultramafic rocks in the catchment area and to the regional technogenic (smelting and metallurgy) geochemical signals (Ni–Cr–Co–V–(Fe)). This step uses Enrichment Factor calculation, regression and partial correlation analysis. Third, the metal contamination–receptor sediment interaction is modeled with regression analysis, applied to distinct sediment geochemistry areas, complemented by thermodynamic hydro-geochemical modeling. Finally, a simple but efficient predictive modeling procedure is developed to assess the fate of metal contamination introduced into the heterogeneous fluvial system: stepwise supervised R-mode (between-parameter) cluster analysis is used where metals are added one-by-one to the previously defined sediment–soil parameter clusters (calcareous geochemistry, clay minerals, organic matter). Accordingly, the Pb−Zn−Cd metals associate with carbonates in the stream and alluvial plain sediments, while Ni−Cr−Co−V−(Fe) metals associate with clays, traceable predominantly in the river terrace, just like heavy minerals. Metal(loid)s also tend to be adsorbed to the reactive surfaces of clay minerals and organic matter, especially in river terrace soils. It is concluded that the applied systematic geochemical data analysis and modeling methodology provides an efficient tool for the characterization and modeling of the complex processes of regional historical metal contamination impacting a heavily disturbed soil–sediment system of a large-river fluvial terrain.

@article{doi101007s12665025125700,
    author = "Szabó, Péter and Jordan, Gyozo and Kardos, Levente and Šajn, R. and Alijagić, Jasminka",
    title = "A geochemical modeling approach from receptor modeling to contamination source fingerprinting. Characterization of sediment-contamination processes altered by river regulation in the Drava River floodplain impacted by historical mining in the Alps mountains",
    year = "2025",
    journal = "Environmental Earth Sciences",
    abstract = "This study presents a systematic geochemical modeling methodology using a combination of data analysis techniques suitable for the predictive modeling of metal contamination processes in altered, heterogeneous fluvial sediment system as contamination receptor. Unlike conventional studies, this approach first characterizes the receptor fluvial sediments using (1) major ions (Fe, Al, K, Na, Ca, Mg, P), indicative of sediment mineralogy; and (2) standard soil parameters (pH, electrical conductivity, loss-on-ignition, CaCO 3 content, clay content), indicative of sediment chemistry, controlling metal behavior (e.g. adsorption, precipitation). In addition to unsupervised hierarchical cluster analysis and Q-mode (between-sample) principal component analysis, multivariate homogeneity tests such as the Mann−Whitney and Kruskal−Wallis median tests identify and verify distinct, geochemically homogeneous areas which, in this study, correspond to the contemporary riverbed sediments, the post-river regulation active alluvial plain, and to the old terrace developed under braided–meandering pre-river regulation conditions of the Drava River. The main geochemical processes in the receptor floodplain soils and sediments, characterized by associations of major ion concentrations and soil parameters, modeled with regression, partial correlation analysis and correlograms are: (1) calcareous geochemistry: Ca−Mg−pH−(CaCO 3 content), in the stream and alluvial plain sediments, defined by the regional geochemical background, (2) clay minerals (sericite–illite): K−Al−Fe−(Mg, clay content), in the river terrace soils, while (3) organic matter: loss-on-ignition−electrical conductivity−P, dominates the topsoil geochemistry in the floodplain. Second, the contamination source is modeled by geochemical fingerprinting using (1) metal associations, characteristic to the upstream mines of the Mississippi Valley-type Pb–Zn–Cd deposits such as the minerals wulfenite Pb(MoO 4), descloizite PbZn(VO 4)(OH), and pyromorphite Pb 5 (PO 4) 3 Cl, and (2) metal associations, characteristic to mafic–ultramafic rocks in the catchment area and to the regional technogenic (smelting and metallurgy) geochemical signals (Ni–Cr–Co–V–(Fe)). This step uses Enrichment Factor calculation, regression and partial correlation analysis. Third, the metal contamination–receptor sediment interaction is modeled with regression analysis, applied to distinct sediment geochemistry areas, complemented by thermodynamic hydro-geochemical modeling. Finally, a simple but efficient predictive modeling procedure is developed to assess the fate of metal contamination introduced into the heterogeneous fluvial system: stepwise supervised R-mode (between-parameter) cluster analysis is used where metals are added one-by-one to the previously defined sediment–soil parameter clusters (calcareous geochemistry, clay minerals, organic matter). Accordingly, the Pb−Zn−Cd metals associate with carbonates in the stream and alluvial plain sediments, while Ni−Cr−Co−V−(Fe) metals associate with clays, traceable predominantly in the river terrace, just like heavy minerals. Metal(loid)s also tend to be adsorbed to the reactive surfaces of clay minerals and organic matter, especially in river terrace soils. It is concluded that the applied systematic geochemical data analysis and modeling methodology provides an efficient tool for the characterization and modeling of the complex processes of regional historical metal contamination impacting a heavily disturbed soil–sediment system of a large-river fluvial terrain.",
    url = "https://www.semanticscholar.org/paper/08f5d89ebcb43e875bef8cca7ece6c20e48dcc40",
    doi = "10.1007/s12665-025-12570-0",
    is_oa = "true",
    number = "21",
    semanticscholar_citation_count = "2",
    semanticscholar_id = "08f5d89ebcb43e875bef8cca7ece6c20e48dcc40",
    volume = "84"
}

@article{doi103133sim3532,
    author = "McGuire, Virginia L. and Strauch, Kellan R. and Wojtylko, Erik A. and Asquith, William H. and Nottmeier, Anna M. and Thomas, Judith C. and Tollett, Roland W. and Kress, Wade H.",
    title = "Altitude of the potentiometric surface and depth to water in the Mississippi River Valley alluvial aquifer, spring 2022",
    year = "2025",
    journal = "Scientific investigations map",
    url = "https://doi.org/10.3133/sim3532",
    doi = "10.3133/sim3532",
    openalex = "W4409499782",
    references = "doi103133sim3439"
}

@incollection{crossrefNonethe,
    title = "The Speed of Light and Classical Physics",
    year = "None",
    booktitle = "The Curious History of Relativity",
    url = "https://doi.org/10.2307/j.ctv39x6bc.5",
    doi = "10.2307/j.ctv39x6bc.5",
    pages = "4-23"
}