近50a西北地区年径流变化反映的区域气候差异

应用我国西部主要河流1951—2000年年径流资料,分析径流变化的区域特征.结果表明:中国西部地区大部分河流径流呈增加趋势,特别是天山南坡逐河流增加最为显著,最高达14%.(10a)-1,其年径流的变化过程相关分析和差积曲线显示,西北地区西部新疆地区与东部的黄河上游年径流变化呈反相变化特征,而西北地区东部河流径流变化则与黄河上游的径流呈正相关关系.西北地区东部黄河年径流和西北太平洋夏季季风指数及其差积曲线表现出一致的变化过程,这表明了黄河上游径流变化主要受东亚季风的影响,同时由于东亚季风与西风在西北地区的相互作用,间接的影响到了新疆地区的径流和降水.这从一个侧面反映的西风带、东亚季风和高原季风的相互作用.

Regional Parttens of Climate Change in Northwest China during the Last 50 Years Viewed from Annual Discharge Change

The water resources are one of the key factors to restrict the development of economy and society in Northwest China,and so its research is very important.In this paper the regional characteristics of climate change are analyzed from the annual discharge change using the annual discharge data at the main rivers over the Northwest China during the last about 50 years.The increased discharge occurred at most rivers over the Northwest China during the last 50 years,especially at some rivers in south slopes of the Tianshan Mountains,where the maximum increasing rate reached 14%\5(10a)~-1.The annual discharge and its residual mass curves show that the discharge have a inverse relationship between Xijjiang Region,the west part of Northwest China,and the upper Yellow river,East part of the Northwest China.The correlation of annual discharge between the upper Yellow River and other main rivers in Northwest China shows that there is a significant negative correlation in the middle and northern areas of Xinjiang Region, while there is a positive correlation in east regions of the Northwest China.A further analysis shows that the annual discharge of the upper Yellow River has good relationship with the index of western North Pacific summer monsoon.This implies that the discharge/precipitation in the middle and northern Xinjiang Region affected by the westerly is also affected by the Asian monsoon,or by the interaction of westerly and Asian monsoon.