Timely prediction of a landslide dam breach is particularly important for assessments of expected disaster consequences and to plan emergency responses. However, due to the complex composition and specific geotechnical properties of the landslide dam material, such a prediction is challenging. In this study, geological survey results and landslide dam breach mechanisms were used to develop a numerical model for overtopping-induced landslide dam breaches, considering variation of soil erodibility with depth. The model included a hydrodynamic process module, a soil erosion module, and a breach evolution module. Moreover, a time step iteration algorithm was adopted to simulate the soil and water coupling process during dam breach. A comparison of calculated and measured breach hydrographs, variations of dammed lake water level, breach sizes, as well as two other typical models were used to validate the rationality of the numerical model, by considering the Baige landslide breach case of November 3, 2018 with detailed measured data. Parameter sensitivity analysis showed that the soil erodibility coefficient exerted an important influence on the breach process, while soil critical shear stress had a relatively small influence (which remained within ±15% for output parameters when it was multiplied by 0.5, 1.0, and 2.0). Furthermore, spillway excavation was found to significantly reduce the peak breach flow if the dammed lake has a large storage capacity, thus identifying it as an effective measure for disaster mitigation.

对滑坡大坝破坏的及时预测对于评估预期的灾难后果和计划应急响应尤为重要。但是，由于滑坡坝材料的复杂组成和特定的岩土特性，这种预测具有挑战性。在这项研究中，考虑到土壤易蚀性随深度的变化，利用地质调查结果和滑坡溃坝机理建立了一个由上覆引起的滑坡溃坝的数值模型。该模型包括一个流体动力学过程模块，一个土壤侵蚀模块和一个破坏演化模块。此外，采用时间步长迭代算法来模拟大坝溃决过程中的水土耦合过程。计算和测量的违规水位图，堰塞湖水位变化，违规规模，通过考虑2018年11月3日发生的Baige滑坡事件和详细的测量数据，使用其他两个典型模型来验证数值模型的合理性。参数敏感性分析表明，土壤易蚀性系数对破坏过程具有重要影响，而土壤临界剪切应力的影响相对较小（当乘以0.5、1.0和2.0时，输出参数保持在±15％以内） 。此外，如果堰塞湖具有大的存储容量，则发现溢洪道开挖可显着降低洪峰流量，因此将其确定为减轻灾害的有效措施。2018年有详细的测量数据。参数敏感性分析表明，土壤易蚀性系数对破坏过程具有重要影响，而土壤临界剪切应力的影响相对较小（当乘以0.5、1.0和2.0时，输出参数保持在±15％以内） 。此外，如果堰塞湖具有大的存储容量，则发现溢洪道开挖可显着降低洪峰流量，因此将其确定为减轻灾害的有效措施。2018年有详细的测量数据。参数敏感性分析表明，土壤易蚀性系数对破坏过程具有重要影响，而土壤临界剪切应力的影响相对较小（当乘以0.5、1.0和2.0时，输出参数保持在±15％以内） 。此外，如果堰塞湖具有大的存储容量，则发现溢洪道开挖可显着降低洪峰流量，因此将其确定为减轻灾害的有效措施。