长江源高寒区域降水和径流时空变化规律分析

Spatial and temporal Variations of Precipitation and Runoff in the Source Region of the Yangtze River

长江源区位于川西北高原东北部,过去40多年来,在全球变暖背景下,该区域冻土-生态环境系统发生了显著变化,尤其是径流过程的变化影响到了长江源区的水源涵养功能。本文利用长江源区沱沱河、五道梁、治多、曲麻莱和玉树5个水文气象代表站的相关数据,采用数理统计方法,分别对长江源区的降水和河川径流的年内、年际和年代际的多尺度时间变化规律进行了分析,并从距平值上探讨了各站的降水量和径流量的空间分布。为进一步研究长江源区流域水资源安全和生态环境问题,以及深入开展长江中下游水资源的可持续利用和保障三峡库区的生态安全有着十分重要的科学价值和现实意义。

The source region of the Yangtze River lies to northeast of the Northwestern Plateau in Sichuan,which is one of the most important areas of the Three-River headwaters region in China. In the recent 40 years, the frozen earth ecological environment system in this area has changed greatly with climate warming. Particularly, the annual runoff decreased continuously, and the variation of the runoff had affected the function of conservation on water supply in the source region of the Yangtze River at the same time. Therefore,it is urgent to study the spatial- temporal variation of the runoff in the source region of the Yangtze River. Based on the data from the hydrologic and meteorological stationsin cluding Tuotuo River,Wudaoliang, Zhiduo, Qumalai and Yushu, a multiple time scales analysis has done to show the annual, inter-annual and decadal variations of the precipitation and runoff. Furthermore, the calculating results showed that annual runoff of the source region of the Yangtze River changed with precipitation, the runoff seasonal distribution focused from May to October and had a reducing trend,and decadal changes of runoff did not show obvious trend. These results have a very important scientific value and a practical meaning to the further study on the water resources security and the ecological environment in this area, the sustainable utilization of water resources in the middle and lower reaches of the river, and the security of the regional ecosystem in the Three Gorges reservoir area especially.