青铜峡水库上游黄河流域气候变化趋势分析

An Analysis of Climate Change Trend in Qingtongxia Reservoir Upstream Region of Yellow River Basin

利用青铜峡水库上游区域31个气象观测站1959—2007年的气象资料,对青铜峡水库上游区域的气候背景及其变化趋势进行了分析。结果表明:青铜峡水库上游区域年平均年降水量为382.3 mm,年蒸发量为896.3 mm,蒸发量是降水量的2.3倍,年平均气温为5.4℃。从历史演变来看,青铜峡上游区域年降水量呈现弱的下降趋势,年蒸发量呈现弱的上升趋势,年降水量和年蒸发量的下降和上升趋势不显著;而年平均气温显著升高。从各季来看,春季降水量显著减少,冬季降水量显著增多,夏、秋季节降水量变化趋势不显著;四季蒸发量的变化趋势都不显著;各季平均气温都显著升高,冬季升高最显著。总体来看,在气候变暖背景下,降水量略有减少,蒸发量略有增加,可利用的水资源总量有所减少,这使得水资源更加短缺,水资源供需矛盾更加突出,对水库运行极为不利,因此亟待加强节水工程建设。

An Analysis is made on the climate background and change trend in the Qingtongxia reservoir upstream region using the meteorological data during the year 1959 to 2007, of 31 observational stations in the Qingtongxia reservoir up-stream region. The result indicates that in the Qingtongxia reservoir upstream region the annual precipitation and evaporation is 382.3 mm and 896.3 mm,respectively,and the latter is 2.3 times of the former; The annual average temperature is 5.4℃. As for the historical development evolutionin the Qingtongxia reservoir upstream region, the annual precipitation appeared weak downward trend and the annual evaporation appeared weak upward trend,and both the trends were not significant. But the annual average temperature rose significantly. As for various seasons,the precipitation in spring declined and increased in winter significantly,while in summer and autumn its variability trend is not significant. The change trend of evaporation was not significant in four seasons, while the annual average temperature rose significantly in every season and most significantly in winter. Generally speaking,under the background of the global warming,the precipitation declines slightly and the evapo-ration increases slightly. So totally the usable water resource decreases to some extent and this makes the water resource shortage more serious. The imbalance between the supply and demand of the water resource is more conspicuous and this is very disadvantageous to the operation of the reservoir. So it is urgent to strengthen the water-saving engineering construction.