Bottom Transformation and Sand Transport Rate on Two-Dimensional Wave-current Coexistent System

Abstract

River mouth closing is one of several troubles which are caused by an interaction between the incident waves and the opposing river flow. This is closely associated with the formation of sand bar near the river mouth. In order to solve these problems, it is necessary to have a deep understanding of sand movements occurring in the wave-current field.
This paper describes the results of the experiments on bottom transformation in a two dimensional wave-current coexistent system, and examines the distributions of the sand transport rates which induce the bottom profile change.
First, we proposed a method of calculation to predict the position and the scale of river-mouth sand bar on the basis of the experimental results.
Second, we classified the distribution patterns of the sand transport rate into three categories.
Third, we proposed a new criterion to judge the predominant direction of the sand transport on the wave-current coexistent system.
Fourth, the calculations of the distributions of the sand transport rate using the above relations have a good agreement with the experimental results.