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https://hdl.handle.net/11681/13098
Title: | Engineering geology and geomorphology of streambank erosion. Report 2, Yazoo River Basin Uplands, Mississippi |
Authors: | Whitten, Charlie B. Patrick, David M. |
Keywords: | Engineering geology Geology Geomorphology Rivers River basins Watersheds Streams Erosion Bank erosion Yazoo River (Miss.) |
Publisher: | Geotechnical Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | Technical report (U.S. Army Engineer Waterways Experiment Station) ; GL-79-7 rept. 2. |
Description: | Technical Report Abstract: Streambank erosion is occurring at an excessively fast rate in the upland or hill region of the Yazoo River Basin in northwest Mississippi . Four streams--Perry, Tillatoba, Goodwin , and Hotopha Creeks--were selected as study sites to determine the cause or causes of the excessive bank erosion. All four streams are located along or close to the bluff line. Historical comparative analyses were used to identify significant changes in stream and basin geomorphology and to detect mechanisms that produced or could produce these changes. Chronological sequences of aerial photographs, field observations, maps, and survey data were the principal means used to measure the basic hydraulic and geomorphic conditions that define the fluvial geomorphic system. Stream width, stream depth, channel slope, and sinuosity were the more easily measurable variables, but general observations about the flow, sediment discharge, and sediment size could also be made. The chronological sequence of historic events that affected the hydraulic and geomorphic conditions are: a.) Land use practices in the Delta from the 1800' s to the present increased flow and sediment discharge. b.) Land use practices in the uplands during the 1800' s and early 1900's increased flow and sediment discharge. c.) Channelization during the early 1900' s increased channel slopes. d.) Meander cutoffs made on the Mississippi, Yazoo, Tallahatchie, and Coldwater Rivers from 1921 to 1953 increased channel slopes. e.) Conservation practices begun in the late 1930's decreased flow and sediment discharge in the uplands. f.) The construction of flood-control dams on the four major streams draining the Yazoo River Basin uplands during the 1940's and 1950's along with associated channelization below the dam increased degradation below the dam by increasing the channel slope and the release of sediment-free water below the dam. g) Continued channelization of streams since the 1940's has increased channel slopes. These changes in hydraulic and geomorphic conditions have caused streambed and streambank erosion as the streams adjust to the changes. Channelization has been the factor most responsible for streambed and streambank erosion. All of the major streams and many of the tributaries in the Yazoo River Basin and the Mississippi River Basin have been channelized to some extent. The stream distance to zero-base level (Gulf of Mexico) has been shortened approximately 10.5 to 13.6 percent. Channel degradation believed to be caused by the increased gradient and to a lesser degree the other mentioned causes is advancing up the major channels and their tributaries. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/13098 |
Appears in Collections: | Technical Report |
Files in This Item:
File | Description | Size | Format | |
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TR-GL-79-7-V2.pdf | 18.96 MB | Adobe PDF | ![]() View/Open |