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

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.