Modeling Non-Uniform-Sediment Fluvial Process by Characteristics Method

Abstract

This paper presents a numerical model based on a multimode characteristics method for fully coupled simulation of water and sediment movement in mobile-bed alluvial channels with nonuniform bed materials. Along with the characteristics, the temporal evolutions of flow depth and velocity, bed elevation, and bed-material composition of a well-defined river reach with proper boundary conditions can be simultaneously determined. From the results of the test runs, the proposed model provides useful information about the interactions among disturbance waves of different orders of magnitude and their influence on the formation of flow field, bed topography, and bed-material composition. Such information cannot be easily obtained from finite-difference methods.