Analysis on Runoff Variation Characteristics of Kaiken River Basin in Xinjiang

According to gauging discharge of the representative hydrologic station which lies in the exit of Kaiken River in Xinjiang,this paper analyzes both distribution and variation characteristics over years of runoff,using variance analysis,regression analysis and Mann-Kendall test.The results show that the intra-annual distribution of runoff comparatively even with 83.7% of years’ concentration degree is above 50%,which indicates that the main supply sources of runoff are rainwater and thawy water from glacier（seasonal snow）.On the one hand,the runoff volume mainly concentrates in the flood season （April to September） with the largest volume appears in June,at the same time,the runoff volume in spring is more than that in winter.While on the other,the variation coefficient over years is only 0.23 with relative stable runoff volume change.On the contrary,the phasical change of the runoff volume is significant,in 1980s,the Kaiken River turns from low water to high water but without sudden mutation.The annual runoff has significant periodicity and its notable periods are 3 a,14 a,16 a,19 a.