Fluid-Mud Movement and Bed Formation Process with Density Current in Estuaries

Abstract

The movement of fluid mud, which consists of fine cohesive clay on a bottom slope, was investigated by the use of a flume under various conditions of initial concentration of suspension and gradient of the bottom slope. The velocity and density of the fluid mud layer on the slope were measured and the growing and decaying processes of the layer were analytically explained. Based on the experimental results, the mechanism and flow-rates of the fluid mud density currents with or without erosion or deposition were theoretically studied, and the horizontal flux of fluid mud was shown to be estimated by the use of a method developed in this study. Field data suggests that the fluid-mud movement with density currents exists.