What are the contemporary sources of sediment in the Mississippi River?
| Autor: | Michael Church, L. Roberge, Jason A. Leach, Khawaja Faran Ali, Simon D. Donner, M. More, Marwan A. Hassan |
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| Rok vydání: | 2017 |
| Předmět: |
Hydrology
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Floodplain Drainage basin Sediment 010501 environmental sciences 01 natural sciences Geophysics Erosion General Earth and Planetary Sciences Environmental science Soil conservation Sedimentary budget Bank Channel (geography) 0105 earth and related environmental sciences |
| Zdroj: | Geophysical Research Letters. 44:8919-8924 |
| ISSN: | 0094-8276 |
| DOI: | 10.1002/2017gl074046 |
| Popis: | Within the last two centuries, the Mississippi River basin has been transformed by changes in land use practices, dam construction and training of the rivers for navigation. Here we analyze the contemporary patterns of fluvial sediment yield in the Mississippi River basin using all available data in order to assess the influence of regional land condition on the variation of sediment yield within the basin. We develop regional scale relations between specific sediment yield (yield per unit area) and drainage area to reveal contemporary regional sediment yield patterns and source areas of riverine sediments. Extensive upland erosion before the development of soil conservation practices exported large amounts of sediment to the valleys and floodplains [Trimble, 1981; Belmont et al., 2011]. We show that sediment today is sourced primarily along the river valleys from arable land, and from stream bank and channel erosion, with sediment yields from areas dominated by arable land two orders of magnitude greater than that of grassland dominated areas. Comparison with the “T factor”, a commonly quoted measure of agricultural soil resilience suggests that the latter may not reflect contemporary soil loss from the landscape. |
| Databáze: | OpenAIRE |
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