Abstract：The Kala hydropower project，with an installed capacity of 1 080 MW，is located in the middle reach of Yalong River in Liangshan autonomous prefecture，Sichuan Province. The river section where the dam is located is mainly composed of consequent strata of sandstone and slate. The valley slopes are intercalated with hard and soft rock stratum，with well developed erosion gullies and strong physical geology process. Within the 16 km-long river section，9 large landslides with a total volume of 772.05×106 m3 are developed. Due to the steep river banks，the rapid river flow，the narrow valley and the large landslides，any landslides might result in serious reservoir sedimentation or river blockage，and thus endanger the dam and other project structures. Therefore，the stability of these landslides and their influences become the critical factors for the selection of dam site. Stability analysis for the landslides is carried out based on the studies of the geology background，and stability of typical landslide is calculated with limit equilibrium method；potential influences on the project in case of landslide failure are studied based on the analysis and calculation of the landslide scale and their possible surges. Finally，following the principle of “first avoiding then treating”and with the comprehensive considerations of the water power utilization and construction condition of the project，recommendation on dam site selection and suggestions for the subsequent works are proposed.
