Runout analysis of a potential debris flow in the Dongwopu gully based on a well-balanced numerical model over complex topography

Abstract

Debris flows could cause large amounts of damage in the alluvial fan where many houses and transport infrastructures exist. Thus, runout analysis of potential debris flows in these areas is necessary for protecting human lives, houses and infrastructure. Currently, the numerical simulation method is an effective way to intuitively display the runout of a potential debris flow. In this paper, a well-balanced finite volume scheme over complex topography was employed for studying the runout of a potential debris flow in the Dongwopu gully. Through model testing and validation, the numerical model had a good potential to adapt to the complex topography and could reasonably simulate the runout of debris flow events. Then, runout distance and inundation path, as well as flow depths and flow velocities, for the potential debris flow were obtained using the model. The simulation results appropriately reflected the runout characteristics.