Sediment sorting in stony debris flow
Due to the combination of steep topography, heavy rain, and high population densities, many debris flow disasters cause serious damage in Japan. Every effort has been made to prevent or mitigate such debris flow disasters. Studies have shown that the larger particles in a debris flow are concentrated at the front of the flow, while finer particles are concentrated toward the rear. This increases the destructive power of the debris flow, and has been explained as the result of vertical sediment sorting. The larger particles tend to move upward in a stony debris flow. The velocity of the upper region is much greater than that of the lower region, so that the material in the upper region is transported faster and is concentrated at the flow front. In this paper, we propose a one-dimensional numerical simulation model for stony debris flow that reproduces the sediment sorting and concentration of coarse particles at the front of the flow. We considered two vertical layers in the model to simulate the upward movement of larger particles, and determined the change in the ratio of coarse particles. The model was verified with the results of flume experiments of mixed debris in the flow using grain sizes of 2 to 15 mm.
stony debris flow sediment sorting two-layer model
Y. Satofuka T. Iio T. Mizuyama
Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Japan
国际会议
成都
英文
121-129
2007-05-17（万方平台首次上网日期，不代表论文的发表时间）