Earthquake or rainfall can arouse landslide, which will cause debris flow. Free surface water waves generated by plunging of debris flow cause devastating damage on human life. In this study, a numerical scheme for debris flow and free surface water wave was developed based on shallow water approximation, in which the interaction between these two flows was included newly. Generation of waves by plunging of debris flow is highly non-linear phenomena. Original CIP method and first order up-wind scheme mixed with second order central derivative scheme were adopted to simulate collision of two initially separated fluids (debris flow and still water). Six cases have been adopted to simulate the generation, propagation and run-up of water waves generated by debris flow. The time series of these two flows for these six calculating cases show the interaction of these two flows. Numerical results for interaction of debris flow and generated water wave are quite satisfactory and reasonable.
An absorbing boundary condition for free surface water waves
