Numerical simulation of Hongchun gully debris flow based on the coupling of LHT model and Pudasaini model

Abstract Numerical simulation is an important means to reproduce debris flow disaster, and a reasonable model can completely reflect the risk and influence area of the whole process from startup to accumulation of debris flow. In this paper, LHT model and Pudasaini model are adopted to realize dynamic whole-process simulation of debris flow. LHT model can reflect the dynamic volume change of shallow landslides under rainfall conditions, and solve the problem of starting location and starting volume of debris flow. The Pudasaini model simulates the volume change of debris flow in the process of movement according to the start-up condition and boundary conditions. The simulation results showed that Hongchun gully was subjected to rainfall on August 12, 2010 solstice and August 14, 2010. The maximum change of landslide volume occurred near 3:00 on the 14th, which was consistent with the actual starting time of debris flow. At the same time, the accuracy of debris flow accumulation volume and area is verified, and the simulation results are excellent. Good simulation results show that the coupling of LHT model and Pudasaini model can completely reproduce the formation process of "8·14" Hongchun gully massive debris flow. It provides an effective simulation method for debris flow formation under rainfall conditions.