关键词: 冰川, 突发性洪水, 洪水成因

Abstract: It is little possible that the glacier-outburst flood would oc-cur in 1987．The reason given as below：first, the glacier dammed lake was just released water last year and it was empty on June thirteenth day, this year when we explored the lake；second, the air temperature is 2-4℃ lower than the other years；It will not be more than 2500³ m/s , if flood occur in 1987, because the total of the lake can only store wa－ ter 6000 m³ and stored as much as it can did before 2130 m³/s flood occurred last year．The tendency of this discharge of Jokulhlaups is decreasing because the size of the lake is reducing as the thickness of the glacier-dam geadually go-ingdown.
The glacier-melting floods is as usual, and the total of the run-off is probably lower than usual, because the air temperature is lower in the carly part of the year.
The average of the run-off will not be reduced in the Yarkand River within this century