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Trends in suspended-sediment loads and concentrations in the Mississippi River Basin, 1950–2009

Scientific Investigations Report 2011-5200

Prepared in cooperation with the National Water-Quality Assessment Program
By:
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Abstract

Trends in loads and concentrations of suspended sediment and suspended sand generally were downward for stations within the Mississippi River Basin during the 60-, 34-, and 12-year periods analyzed. Sediment transport in the lower Mississippi River has historically been, and continues to be, most closely correlative to sediment contributions from the Missouri River, which generally carried the largest annual suspended-sediment load of the major Mississippi River subbasins. The closure of Fort Randall Dam in the upper Missouri River in 1952 was the single largest event in the recorded historical decline of suspended-sediment loads in the Mississippi River Basin. Impoundments on tributaries and sediment reductions as a result of implementation of agricultural conservation practices throughout the basin likely account for much of the remaining Mississippi River sediment transport decline. Scour of the main-stem channel downstream from the upper Missouri River impoundments is likely the largest source of suspended sand in the lower Missouri River. The Ohio River was second to the Missouri River in terms of sediment contributions, followed by the upper Mississippi and Arkansas Rivers. Declines in sediment loads and concentrations continued through the most recent analysis period (1998–2009) at available Mississippi River Basin stations. Analyses of flow-adjusted concentrations of suspended sediment indicate the recent downward temporal changes generally can be explained by corresponding decreases in streamflows.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Trends in suspended-sediment loads and concentrations in the Mississippi River Basin, 1950–2009
Series title:
Scientific Investigations Report
Series number:
2011-5200
Year Published:
2011
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Missouri Water Science Center
Description:
vi, 33 p.
Time Range Start:
1950-01-01T12:00:00
Time Range End:
2009-12-31T12:00:00
Country:
United States
Other Geospatial:
Mississippi River Basin
Online Only (Y/N):
Y