金沙江美姑河牛牛坝水电站库区泥石流对工程影响分析

IMPACTS OF DEBRIS FLOWS ON THE RESERVOIR OF A HYDROPOWER STATION IN THE MEIGU RIVER OF JINSHAJIANG

金沙江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;这些泥石流不会造成严重的堵河问题。在施工期泥石流对水电站工程的影响突出,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,库区泥石流对水电站工程影响有所降低,但位于大坝下游区的泥石流对水电站正常运行仍有较大的影响。

The debris flows have a wide distribution and frequent occurrence in the reservoir of a hydropower station, which is located in the Meigu River of Jinshajiang. The survey results show there are 31 debris flow valleys of different types in the reservoir area. Among them, 4 valleys are classified as at a high hazard level, and 15 are at a moderate hazard level. The results indicate the debris flow activities in the study area will not result in blocking of the main channel that possibly brings about flood in the downstream of the river. However, debris flow hazards have a great potential impact on the hydropower station during the engineering construction. Debris flow valleys near the dam pose a great potential threat to the dam safety. After inundation of the reservoir, most debris flow hazards will be reduced to an acceptable level, but debris flows in the lower reaches near the dam still have influence on operation of the hydropower station.