Risk prevention and control of landslide-generated impulse waves in Wangjiashan area of Baihetan Reservoir on Jinsha River, China

Economically and effectively managing the risk of landslide-generated impulse waves (LGIWs) presents a significant challenge following the impoundment of newly constructed reservoirs in western China. To address this issue, we selected the Wangjiashan (WJS) landslide in the Baihetan Reservoir area as a case study to evaluate LGIW hazards and develop corresponding mitigation strategies. Using 2D physical model tests and 3D numerical simulations, we established a 3D hazard assessment method for LGIWs based on 2D experimental results. This method confirmed the effectiveness of slope-cutting engineering in mitigating LGIW hazards. Based on this assessment framework, we proposed a novel approach for LGIW risk reduction. The results showed that the maximum wave amplitude reached 19.64 m in the Jinsha River channel, and the maximum run-up was 11.5 m in the XiangBiLing (XBL) community, indicating a substantial LGIW threat to the area. By reducing the rear edge of the sliding mass to 920 m above sea level (asl), the LGIW risk to the XBL community could be lowered to a tolerable level. Compared with traditional landslide prevention and control measures, the proposed mitigation scheme can reduce excavation costs by approximately 37 million CNY, making it a more scientifically sound and economically feasible solution. We explored the concept and the implementation of LGIW risk mitigation in depth, offering new insights for global LGIW risk management. This case study enhances our understanding of LGIW hazard prevention and provides valuable guidance for policymaking and engineering practices in similar geological settings worldwide.