Effectiveness Evaluation of Debris Flow Control and Mitigation Strategies for Cascade Hydropower Stations in Upper Yangtze River, China—A Case Study in Baihetan Hydropower Station of Jinsha River
[Objective] The objective of the study is to evaluate the effectiveness of debris flow disaster control project in development zone at cascade hydropower stations at severe landslides-affected Upper Yangtze River and provide references on effectiveness post-evaluation of debris flow control for other hydropower stations. [Methods] The Aizi and Dazhai gully debris flow regulation engineering in Jinshajiang River were chose as a case. The peak flow process of Aizi and Dazhai gully debris flow were calculated through the tracking investigation of three consecutive years from 2013 to 2015. The effectiveness of debris flow control engineering of Aizi and Dazhai gully in 2014 and 2015 were evaluated. The risk of debris flow was estimated. [Results] Post-evaluation model on effectiveness of debris flow control in the cascade hydropower stations of Upper Yangtze River development zone was put forward based on the results of the assessment system. The governance model of debris flow and mitigation strategies were proposed based on the water and electricity engineering debris flow risk control according to the characteristics of debris flow hazards in the development of cascade hydropower stations in the Upper Yangtze River. [Conclusion] Existing debris flow prevention and control measures of Aizi and Dazhai gully can meet flow requirements of five hundred-year debris flow under the conditions of impletion, and debris flow risk is less in the area.