Movement of Finite Amplitude Sediment Accumulations

The movement of finite amplitude sediment accumulations is studied using a simple advection-diffusion relation derived from the sediment continuity equation and using some heuristic reasoning. The movement of a finite amplitude sediment accumulation is found to be strongly diffusive with a small advection component due to the increase in transport rate of the sediment accumulation relative to the transport rate of the original bed material. A semianalytical solution to the advection-diffusion equation is found and the equation is applied to two laboratory experiments. The equation is found to predict the general movement of finite amplitude sediment accumulations with a minimal number of parameters.