Hazard Assessment of Landslide Surge in front of Narrow River Dams

In response to the insufficient study on landslide surges in narrow river channels near the dam area, based on the Baoxing power station, this paper uses the FLOW-3D numerical analysis method to analyze the propagation characteristics, disaster characteristics, and hazard of surges in the near dam area on different landslide scales. The results show that the volume of the sliding slope is directly proportional to the first wave height, the range of harm, and the degree of hazard caused by the surge. At normal water level (1 352 m) and check flood level (1 348.8 m), landslides with sliding volumes of 35 000 m³ and 150 000 m³ can generate surge heights of 1.41 and 4.81 m, respectively. The surge height approaches or exceeds the dam crest. There is a high risk of dam overflow and surge hazard. It can be considered as the critical landslide volume for the safe operation of the dam under the above water level conditions. Compared with the relatively high water level, the relatively low one can provide climbing space for the surge caused by large sliding bodies. To reduce the risk of dam overflow, it is recommended to lower the operating water level of the power station during the prone period of landslide disasters.