Based on the Herschel-Bulkley rheological theory, the governing equation describing the viscoplastic debris flow has been solved by finite volume method, which can model the landslide process. The landslide model is coupled with the nonlinear shallow water equation model including the moving bottom boundary conditions to constitute landslide tsunami model. The generation, propagation, run up and inundation of landslide tsunami can be computed numerically. The 1998 Papua New Guinea landslide tsunami was simu...