长江源流量对长江源流域气候年代际变化的响应

Response of Runoff to Interannual Climate Change over Changjiang River Source Region

利用长江源流域气象站降水、气温资料和源区直门达水文站流量,建立了历年各月、季降水距平百分率和气温距平序列,分析了长江源流量与长江源流域降水、气温的年代际变化。结果表明,长江源流域气候演变存在非常明显的年代际变化。年降水量呈平缓下降趋势,60、80年代年降水量正常或偏多,70、90年代偏少,主要受夏季降水的影响;年气温明显呈上升趋势,60年代最冷,70年代开始回升,80年代暖在冬,90年代暖在秋,目前年、夏、秋、冬季已达到1961年以来的最暖期;年流量与年降水的年代际变化、突变年份对应,60、80年代偏多,70、90年代偏少,目前除春季流量外,夏、秋、冬季已转入上升趋势,1965、1979、1997年二者均发生了突变。

The precipitation anomaly pcrcentage series and air temperature anomaly series in each month and season over the Changjiang River source region arc established, and the interannual change of air temperature, precipitation, and runoff is analyzed, based on the precipitation and air temperature data at eight meteorological stations and runoff data at the Zhimenda hydrological station over the Changjiang river source region. The result shows that the climate over the Changjiang River source region has a very significant interannual change. The precipitation amount was normal or greafer than normal in the 1960s and 1980s, and less than normal in the 1970s and 1990s, which attributed mainly to precipitation variation in summer. Annual air temperature has a rising trend, with the coldest period in the 1960s, warm autumns in the 1990s, and warm winters in the 1980s; the warming began from the 1970s and became fast after the 1990s. Presently, the annual, summer, autumn and winter temperatures are the highest since 1960s. The annual runoff corresponded to theinterannual change and abrupt change years, greater than normal in the 1960sand 1980s, less than normal in the 1970s and 1990s. Except in spring, the runoffs in summer, autumn and winter start to rise at present, and there were abrupt changes in 1965, 1979 and 1997.