雅砻江流域径流演变特征及成因

利用M-K检验、滑动t检验等方法系统地分析了雅砻江流域两河口、锦屏、官地和二滩4个水文站点径流情况,研究其年内分配、年际变化、趋势特征、突变点等径流过程变化特征,并探讨其成因。结果表明,雅砻江流域年内径流量主要集中在6～10月,约占年径流总量的75.46%;各站点年径流量整体呈下降趋势,从月径流量变化趋势来看,4站均在5、9月呈不显著上升趋势;雅砻江流域径流突变点为1987年,与流域内实际的水利工程建设时间基本一致,两种突变检验方法相结合提高了突变点识别的准确率。气象因素是1953～2011年径流变化的主要驱动因素,但大量水电站的开工与建成导致雅砻江流域径流在1987年发生变化。

Characteristics of Evolution of Runoff and Its Causes in Yalongjiang River Basin

The Mann kendall test and moving t test methods were employed to analyze the distribution of runoff, abrupt change and the change in tendency based on the data from four hydrological stations (Lianghekou, Jinping, Guandi and Ertan) in Yalongjiang River Basin. And the causes of runoff were discussed. The results indicate that the runoff between June and October accounted for about 75.46% of the annual runoff. The annual runoff had a decreasing trend, while in May and September, the monthly runoff had an increasing trend. The abrupt change in runoff occurred in 1987, which was basically consistent with the construction time of hydropower stations in the actual basin. This manifests that the combination of two methods can improve the accuracy of abrupt change recognition. In addition, the meteorological elements were the main driving factors of runoff variations during 1953 2011. But the construction and completion of hydropower stations led to the change in runoff regime after 1987.