美姑河牛牛坝水电站库区泥石流基本特征

金沙江支流美姑河牛牛坝水电站库区泥石流沟分布面积广、发生频率高。调查结果表明库区现有不同类型泥石流沟31条,其中属于高度危险的泥石流沟4条,中度危险的泥石流沟15条。本文对流域面积较大、活动性较强的12条泥石流的容重、设计流速、流量、冲出量等重要工程参数进行了计算,并对水库蓄水后的泥石流沟状况与发展趋势作了进一步分析,研究表明在水库施工期泥石流灾害对工程建设有较严重的影响,特别是靠近库首的泥石流对工程的安全构成威胁。水库蓄水后,库区泥石流活动程度有所降低,不会明显影响水电站正常运行。

Features of Debris Flow in Reservoir of Hydropower Station in the Meigu River of Jinshajiang

Debris flow has a wide distribution and frequent occurrence in reservoir of hydropower station, which is located in the Meigu River of Jinshajiang. The survey results show that there are 31 debris flow valleys with different types in the reservoir zone. Among them, 4 debris flow valleys belong to high hazard level, and 15 moderate hazard level. The debris flow hazards have a great impact on the hydropower station during engineering construction period. The important parameters of debris flow with high activity, such as volume weight, designed velocity, designed discharge, potential depositional amount, are calculated for 12 debris flow valleys. Activity status and development trend of these debris flow are also further analyzed after the reservoir works. The study results indicate that debris flow hazards have great influence on reservoir construction. After the hydropower station begin to work, most debris flow hazards will reduce to acceptable level, which have no obvious impact on working order of the hydropower station.