堰塞体是山区常见的地质灾害，一旦发生溃决，将对下游人民的生命财产安全构成严重威胁.在应急响应时需要对堰塞体溃口流量过程和溃口形态演化进行快速准确的预测，但目前的溃坝数学模型大多未充分考虑堰塞体的地貌学特征，无法合理反映复杂地形下堰塞体的溃决过程.采用雷诺平均Navier-Stokes方程和湍流重正化群k-ε模型相结合的数值方法，对复杂地形下的溃决水流进行模拟，并利用可考虑推移质和悬移质输移的冲蚀公式模拟溃口冲蚀过程，选择拥有详细勘测资料和水文数据的“11•03”白格堰塞体溃决案例进行反演分析.对比计算和实测的溃口流量过程线、溃决过程水动力学特征及最终溃口断面形态发现，模拟结果可较好地反映堰塞体的实际溃决过程，验证了模型的合理性.

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.