Long-Term Simulation of Fine-Grained Sediment Transport in Large Reservoir

Abstract

A 30-year simulation of fine-grained, cohesive sediment transport in Watts Bar Reservoir, located in Tennessee, demonstrated that the SEDZL model realistically predicts overall patterns of erosion and deposition throughout this large reservoir. Good qualitative agreement was achieved between the predicted and observed trends in the net sediment-bed-elevation change during the model-calibration period, from 1961 to 1991. Quantitative comparison of predicted and measured bed elevation changes indicated that the model was generally able to accurately simulate local erosion and deposition within Watts Bar Reservoir, yielding a median absolute relative error of 46% in the cohesive sediment bed areas of the reservoir. The model predicted that 76% of the incoming sediments during this 30-year period would be trapped in the reservoir, which is in excellent agreement with the observed trapping efficiency of 72 ±6% (95% confidence interval).