西藏中波水电站库区泥石流对工程影响研究

Engineering Influence of Debris Flows in the Reservoir Area of Zhongbo Hydropower Station in Tibet

中波水电站位于西藏昌都地区玉曲河下游河段,经调查库区内共发育8条较大泥石流沟谷,是影响水电站施工与运营安全的地质隐患之一。在分析泥石流发育地质环境背景的基础上,评价了各沟泥石流危险程度,并着重从泥石流入汇堵江、冲击淤埋和水库淤积3个方面讨论了其工程影响。研究成果表明:1库区泥石流沟不具备堵江的入汇条件;2泥石流百年内输砂总量301.77万m3,仅占水库总库容的1.125%;3须重点关注近坝的扎拉沟,泥石流危险性大,直接威胁枢纽区施工安全。研究成果对水工设计方案确定和防灾减灾都具有实际的工程意义。

Zhongbo hydropower station is located in the lower reaches of the Yuqu River, Qamdo of Tibet. Investi- gation 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 fo- cus 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.