Erosion, redeposition, and delivery of sediment to midwestern streams

Abstract

While sediment in surface waters may be one of our more serious water quality problems, the sources of this sediment are not well defined. Sediment control programs for water quality are presently concentrating on the application of best management practices (BMP's) across the watershed with little regard to location. The authors have studied sediment movement patterns in a midwestern watershed using fallout cesium-137 techniques and have concluded these programs may be largely ineffective. The implications from this work are that cropped floodplains are the most severely eroded lands in the watershed, followed by cropped lands bordering the floodplains. Most of the eroded sediment either originates on or is delivered directly to the active floodplain and hence to the stream. The authors conclude that the majority of cropped uplands may not be nearly as important in determining sediment levels in streams as is generally thought.