叶尔羌河发源于昆仑山和喀喇昆仑山区,是新疆第三大河。近30年,每2—3年发生一次突发性洪水,给下游人民造成很大灾难。 本文阐述了该洪水的特性,时空分布、演进情势及峰量变化,加之分析气象资料、地质地貌条件,首次提出突发性洪水成因于冰川阻塞湖泄洪,其策源地位于克勒青河上游的克亚吉尔特索湖和特拉木坎力湖。随着冰川的衰退,阻塞湖将逐渐缩小。

The Yarkant River which originates from the Karakoram Mountains is the third Largest river in Xinjiang. The outburst floods often occurring in this river in recent years create hazards to human population, however, the problem about what makes the flood occur has not been solved yet.The purpose of this paper is to explore the major problems concerning the outburst floods.The first problem is to analyze the characteristics of these floods according to their basic features, their distribution in space and time, their situation of evolution, and the statistics of the flood peak and its magnitude.The second problem is that by comparing and analyzing the local meteorological information, the geomorphic condition and the features of these outburst floods, the idea is advanced that these outuburst floods are caused by discharge of the blocked lakes, not by torrential rains. They are different from the normal floods of glacial origin.The third problem is that with the help of air photograph taken in 1976 and the expedition for examining the traces of the floods in the Shaksgam valley, it is bound that the source of the floods is the Kyagar Thso lake blocked lake and Teram Kangri glacier located at the upper end of the Shaksgam vallay.A final problem is to point out that extent of the blocked lake is being reduced because the Kyagar glacier is declining, and to suggeste how to prevent this kind of floods.