雅鲁藏布江径流变化趋势及原因分析

Evolution Trend and Causation Analysis of the Runoff Evolution in the Yarlung Zangbo River Basin

论文利用1956—2000年近45a的天然径流逐月资料,1956—2004年近50a的气温、降水逐月资料,分析了20世纪下半叶雅鲁藏布江流域径流变化特征及其与气候变化的关系。研究表明:雅鲁藏布江流域径流的年际变化较稳定,年内分配极不平衡,月最大径流量占全年百分比达30.1%,而月最小径流量只占全年的2.1%,枯水季节径流量和洪水季节径流量相差较悬殊;雅鲁藏布江流域普遍存在升温的变化趋势,同时流域内降水增加趋势较明显,变化周期与径流变化周期较一致。从雅鲁藏布江流域天然径流代际变化的初步分析来看,流域来水的增加,主要受制于降水和气温的变化,也受到流域地表状况变化的影响,同时也可能是河流丰枯长周期变化的表现。这种周期变化还需相关资料的验证和分析。

This paper makes use of the monthly natural runoff data from1956 to 2000, the monthly air temperature data and precipitation data from 1956 to 2004 to analyze the evolution characteristics of the runoff in the Yarlung Zangbo River basin in the later half of the 20th century and the relation between runoff evolution and climatic change.The results show that the interannual evolution of the runoff in the Yarlung Zangbo River basin is stable,but the intraannual distribution of the runoff is extremely uneven, the maximum monthly runoff accounts for 30.1%, while the minimum runoff only accounts for 2.1%, and indication of the great difference in the runoff between low water season and flood water season.The climate in the Yarlung Zangbo River basin is calefactive, and the increasing trend of the precipitation is obvious, having the same evolution periods with runoff.After elementary analysis of the decadal runoff in the Yarlung Zangbo River basin,we found that the increase of the water supply is mainly controlled by climate change,but is also affected by the changes of the earth surface conditions in the basin and maybe a representation of the long period of variation of high and low stream flow. Relevant data are required to validate and analyze this kind of periodic variations.