Numerical Simulation of Breach Hydrograph and Morphology Evolution during Landslide Dam Breaching

Landslide dam is a common geological disaster in mountainous area.Once breach, it would pose a serious threat to the lives and property safety of downstream people.In emergency response, it is necessary to rapidly and accurately predict the landslide dam breach hydrograph and morphology evolution.However, most of the state-of-the-art numerical models for landslide dam breaching cannot fully consider the geomorphological characteristics of the landslide dam, as well as the breach process under complicated topography.In this paper, the Reynolds-averaged Navier-Stokes equations combined with the renormalization group k- ε turbulence model were used to analyze the breach flow under the complex topography.Meanwhile, the sediment transport equations for bedload and suspended load were employed to simulate the breach morphology evolution process.The“11•03”Baige landslide dam failure case with detailed survey and hydrological data was selected as the representative for back analysis.The comparison of the calculated and measured results on breach hydrographs, hydrodynamic characteristics during dam breaching, and final breach morphologies show that the numerical simulation results can present good performance on landslide dam breach process, which testified to the rationality of the model. © 2023 China University of Geosciences.All rights reserved.