Measurements of Erosion of Undisturbed Bottom Sediments with Depth

Abstract

A unique flume that measures the erosion of sediments at high shear stresses and with sediment depth has been designed, constructed, and used. Experiments in this flume, Sedflume, can be done either with reconstructed sediments or with relatively undisturbed sediments from the field. With either kind of sediment, two different types of experiments can be conducted. The first type determines the critical stress for erosion of the sediment as a function of depth, while the second type determines the erosion rate of the sediment as a function of both shear stress and depth. Measurements of the erosion rates of sediments from the Trenton Channel of the Detroit River in Michigan and the Lower Fox Fiver in Wisconsin were made by use of Sedflume at sediment depths up to 2 m. Representative results of these measurements are presented here. These results demonstrate the capabilities of Sedflume and also illustrate the large differences in erosion rates at different sites and the large variations in erosion rates with depth and as a function of shear stress.