2004 Volume 48 Pages 895-900
Debris flow characteristics such as flow discharge, mean flow velocity, mean sediment concentration, sediment runoff volume and so on are usually predicted by solving the governing equations numerically. Formulas for erosion/deposition rate and flow resistance play important roles in mass and momentum equations. In addition, potential erosion depth and sediment correction factor also affect largely the debris flow characteristics.
The present study emphasizes the importance of the correction factor for sediment concentration and velocity profiles in predicting sediment transport rate and sediment runoff volume. According to Egashira et al.'s theory, sediment is concentrated near the bed, and this non-homogeneity increases with decreasing bed slope. This means the flux sediment concentration of a debris flow differs from the volumetric cross-sectional mean concentration. Correspondingly, sediment runoff volume simulated without a correction factor is very different from actual runoff volume. In this paper, we present a method for predicting the correction factor for sediment discharge, and discuss simulated results of runoff process of debris flow in a flume.
