A TWO LAYER FLOW ANALYSIS OF DEBRIS FLOW CONSIDERING VERTICAL DISTRIBUTION OF VELOCITY AND CONCENTRATION

Abstract

Governing equations of debris flow include correction factors due to vertical distributions ofvelocity and sediment concentration which vary corresponding to bed slope. In this study, the correction factors in governing equations of a two layer model for debris flow proposed by the authors were examined under theequilibriumstate of the flow over a wide range of bed slope. Numerical simulations were carried out on simple conditions to examine effects of the correction factors on erosion and deposition process of debris flows. The term of sediment flux in a mass conservation of the two layer model modified by the correction factor influences stronglyon the erosion and deposition processes of debris flows.