近十年气候变化对黄河中上游水沙影响分析

Preliminary Analysis of the Influence of Climate Changes in Current Decade on Water and Sediment in the Upper and Middle Yellow River

本文针对1986～1995年黄河中上游平均年径流量为50年代以来最小值，而入黄泥沙量却未出现相应减少的异常现象，着重分析了同期的气候背景，发现流域降水、气温，以及与其相关联的西太平洋副热带高压、青藏高原区与印缅槽区的高度场、台风活动等要素都出现了气候突变。自90年代开始热带太平洋发生了百年罕见的持续性长ENSO现象，并连续发生了3次ENSO事件，均属百年罕见。正是由于诸因素的异常变化，从而导致黄河中上游枯水多沙。

Aimed at the abnormal phenomena of that there was the minimum average runoff of 50 yeare since the new China is established in the upper and middle Yellow River area from 1986 t0 1995and however the sediment into the Yellow River was not decreased correspondingly,the climate background is analyzed and emphasized in the paper,and find that there were enormous changes in many climate factors, including precipitation, air temperature in the river basin, and relative to them, the subtropical high pressure in westem Pacffic, height field over the Tibet Plateau and India and Burma trough, typhoon activities, and so on.There had been long ENSO phenomenon and three times of ENSO events in the Pacific tropical region since 1990, which are exceptional over a century. It is the abnormal of those factors that lead to the less runoff and much sediment in the upper and middle Yellow River.