1980—2009年三峡库区空中水资源变化特征

利用1980—2009年三峡库区及周边15个气象探空站的高空资料,分析了三峡库区空中水资源的变化特征,结果表明:三峡库区上空整层水汽含量分布从东北到西南逐渐增加。三峡库区的水汽主要来自西南水汽输送,夏季西南风水汽输送强度最大。三峡库区上空水汽多以辐合为主,尤其在库区西北部和东南部的辐合特征更为明显。三峡库区的水汽主要从南边界流入,而主要从东边界流出。三峡库区各月的净水汽通量都为正值,呈单峰型变化,在7月达到最大值。近30 a,三峡库区净水汽通量经历了明显的先上升后下降的抛物线型年代际变化,春季和冬季的平均净水汽通量整体呈减少趋势,而夏季、 秋季和年平均的净水汽通量呈增加趋势。

Variation Characteristics of Water Vapor Resources over the Three Gorges Reservoir Area during 1980-2009

On the basis of meteorological sounding data at 15 stations in the Three Gorges Reservoir Area(TGRA) and its surroundings from 1980 to 2009,the variation characteristics of water resources in air over the TGRA are analyzed.The results show that the water vapor content increases gradually from northeast to southwest over the TGRA.The water vapor over the TGRA mainly comes from the transportation of southwest water vapor,which has the greatest intensity in summer.There is convergence of water vapor over most of the TGRA,apparently in northwest and southeast of the TGRA.The water vapor over the TGRA mainly inflows from south boundary and outflows from east boundary.The net water vapor flux is positive in each month,showing a single peak changes at maximum in July.The integrated net water vapor transport flux has experienced a parabolic decadal change with first increasing and then decreasing,and had an decreasing trend in spring and winter and an increasing trend in summer,autumn and annual mean in the past 30 years.