Abstract: Zhongbo hydropower station is located in the lower reaches of the Yuqu River, Qamdo of Tibet. Investigation shows that 8 large debris flow gullies develop in the reservoir area. By analyzing the geological environment of debris flows, we assessed the risk degree of debris flows. We also analyzed the impacts of debris flows on the project in detail, such as river blocking, collision siltation and reservoir sedimentation. Results suggest that (1) none of the debris flows have confluence conditions for blocking rivers; (2) the total sediment of debris flows will reach 3,017,700 m³ in the later century, accounting for 1.125% of the total reservoir capacity; (3) we should focus on the Zhala gully near the dam because it has high risk of debris flow and directly threatens the construction safety in the hydro-junction area.The research results are of practical significance for hydraulic design and disaster prevention.

Key words: Zhongbo hydropower station, Yuqu River, reservoir debris flow, development feature, risk degree, engineering influence