Risk assessment on the stability of barrier dam induced by Caijiaba landslide, SW China

摘要

The failure of barrier dams formed by landslides will cause flood disasters, a widespread problem worldwide. To reduce the damage of catastrophe caused by dam break, this research proposes a method to evaluate the barrier dam's stability quickly. This method has been verified in the case of the Caijiaba landslide in Yunyang County, Southwest China. This study uses the fluid continuous motion equation to simulate the propagation range and deposition square quantity of four potential landslide areas. The results show that the four landslides will eventually accumulate in the Longwang River Valley and form barrier dams. Then, combined with the geomorphological index approaches, the stability of the formed barrier dam is evaluated based on the numerical simulation results obtained and the critical value of geomorphic parameters given in the references. It is determined that the Caijiaba landslide cannot form a stable barrier dam in Longwang River, which will not cause dam-break disasters and do little harm to downstream villages. Compared with the existing barrier dam stability evaluation methods, the advantage of the method proposed in this study is that it can quickly obtain accurate evaluation results. Therefore, this method can be applied to the evolution state and stability evaluation of landslide dams with similar geological conditions. Additionally, this method can quickly obtain the evaluation results at a low cost, providing guidance and reference for the emergency early warning and risk assessment of landslide dam break disasters.