The Interdecadal Variations of Climate and Hydrology in the Upper Reach and Source Area of the Yellow River and Their Impact on Water Resources in North China
黄河上游和源区气候、水文的年代际变化及其对华北水资源的影响

The interdecadal variations of climate and their impact on the variations of runoff amount in the upper reach and source area of the Yellow River,and the impact of runoff amount variability in the upper reach of the Yellow River on water resources in North China are analyzed by using the observed data of precipitation and surface air-temperature in meteorological observational stations in China during 1951-2000 and the observed data of runoff amount in hydrological observational stations in the upper reach of the Yellow River during 1960-2003.The analyzed results show that from the 1990s,rainfall slightly decreased and surface air-temperature obviously increased in the upper reach and source area of the Yellow River,which have led to the significant decrease of runoff amount in the upper reach of the Yellow River.Moreover,the decrease of runoff amount in the upper reach of the Yellow River may be an important season of the significant decrease of runoff amount in the lower reach of the Yellow River and the increase of drying-up days of the Yellow River.This can show that the inputing water amount from the upper reach of the Yellow River is an important cause affecting the water resources in North China.