1961～2008年三峡库区气候变化特征分析

CHARACTERISTICS OF CLIMATE CHANGE IN THE THREE GORGES RESERVOIR AREA DURING 1961～2008

利用三峡库区17个气象站1961～2008年各气象要素的资料,系统地分析了库区近48a来的气候变化特征,并探讨了三峡水库的局地气候效应。结果表明:近48a来三峡库区年平均气温为升温趋势,库区增温主要从20世纪90年代开始,且有加快趋势。冬季平均气温升温显著。从平均最高/低气温来看,秋季平均最高气温增温显著。年平均、秋季和冬季平均最低气温升温显著。年降水量整体上表现为弱的减少趋势,秋季减少趋势显著。年、冬季和夏季日照时数均显著减少。年、夏季和冬季平均相对湿度增加趋势显著。年和四季的平均风速都呈显著减小趋势。年降水日数、小雨日数和中雨日数均为线性减少趋势,但趋势均不显著;大雨和暴雨日数无明显变化趋势。年高温日数整体上没有明显的变化趋势,但2001～2008年显著偏多,尤其是2006年为历年最多。三峡水库蓄水后未发现周边地区降水量的明显变化。近库地区的气温在冬季有增温效应,夏季有降温效应。

Based on the various climate factor data from 17meteorological stations during 1961～2008,characteristics of climate change in the Three Gorges Reservoir Area were analyzed,and climate effects after water storage were discussed.The results showed that in recent 48years annual mean temperature increased,and the increase mainly started from 1990s.Mean winter temperature increased significantly.From the annual mean maximum/minimum temperature,autumn mean maximum temperature increased obviously.Annual,autumn and winter mean minimum temperature increased sharply.The change trend of annual rainfall was not obvious and autumn rainfall decreased sharply.Annual,winter and summer sunlight decreased obviously,and annual,winter and summer mean relative humidity increased evidently.Annual and seasonal mean wind speeds decreased markedly.Annual rain days,moderate rain days and light rain days decreased,but the trend was not obvious.Heavy rain days and hard rain days had no obvious trend.High temperature days had no obvious trend,but increased in the period of 2001～2008years,especially for 2006.After water storage,the rainfall in the Three Gorges Reservoir Area seems to have no obvious change.The expanding water surface area of reservoir seems to have increasing temperature effect in winter and decreasing effect in summer.