天山北坡中小河川降水与径流变化特征——以精河为例

Variation features of precipitation and runoff of the middle-small rivers of northern piedmont of Tianshan Mountains:a case of Jinghe River

利用精河山口水文站近50 a(1957-2005年)的气象、水文资料,采用(Mann-Kendall)非参数检验和相关分析法,对天山北坡精河近50 a的降水与径流的变化特征以及径流对降水变化的响应进行了探讨。结果表明:精河流域的径流对降水变化具有很好的响应关系,二者的变化趋势相近。精河流域降水在20世纪70年代出现减少过程,这期间河川径流量也显著减少;80年代以后降水呈现增加趋势,河川径流量也呈现增多趋势,山区降水变化是影响径流变化的重要因子。精河流域的降水、径流变化与我国西北地区气候向暖湿化变化的趋势基本一致,这种向暖湿化方向转变的现象在精河流域始于80年代初期,较塔里木河流域略早。

The influences of climate change on runoff ches in the world. The climate change results in the c processes are of the main topics of the climate change researhange in water circulation and the spatio-temporal redistribution of water resources. In this paper, on the basis of meteorological and hydrographical data for nearly 50 years （1957 -2005 ） of Jinghe River on the north slopes of the Tianshan Mountains, the variation features of precipitation and runoff and their response relationship are analyzed with the methods of nonparametric test and correlation analysis. The main results obtained are as follows ： The annual distribution of runoff volume of Jinghe River and its precipitation is relatively uniform, but its monthly distribution is not so even. The main precipitation and runoff volume of one year are concentrated in summer period. 66.52% of the precipitation and 74% of the runoff volume in one year are concentrated in the concentration-period （from June to September）. Linear correlation analysis of hydrological observation records revealing the tendency of runoff is consistent with precipitation and a best significant positive correlation relationship is presented between precipitation and runoff. The precipitation in the Jinghe River basin had been obviously reduced in the 1970s, and the runoff decreased relatively. The precipitation series showed an increasing trend after 1980s, and the runoff had the same trend. The variation of precipitation in the mountain area is the main reason of affecting runoff variation. The change of precipitation is the most remarkable factor to influence the runoff change in Jinghe River Basin. The climate change towards warming-wetting in Jinghe River basin has a similar trend to that of northwest China and this phenomenon occurred during the beginning of 1980s. This change occurred earlier than that in the Tarim River basin.