三峡水库近20年水面蒸发量分布特征及趋势分析

水面蒸发是三峡水库水体水量损失的主要部分,是研究水库水量平衡的基本要素。收集了三峡水库沿线7个气象局近20年的水面蒸发量观测资料,通过整理和合理性检验后,对三峡水库水体的水面蒸发量以及蒸发能力在空间和时间上的分布特征和变化规律进行了分析。分析成果表明:各观测站水面蒸发量逐月变化规律均一致;水面蒸发量逐年变化呈波动性,年蒸发量在变化过程中有显著下降的趋势。空间变化特征是月水面蒸发量由上游至下游呈现多个峰值和谷值的变化;年蒸发量是库区上游站点年蒸发量偏小,沿程变化从上游沙坪坝到下游巫山逐渐增大,然后从巫山到下游巴东逐渐变小。

Distribution and Trend Analysis of Surface Evaporation in Three Gorges Reservoir in Recent 20 Years

The surface evaporation is the main part of the water loss of the Three Gorges Reservoir, and it is the basic factor to study the waterbalance of the reservoir. This paper collected the data of surface evaporation from 7 meteorological bureaus around the Three Gorges Reservoir,and analyzed the spatial-temporal distribution and surface evaporation of water bodies evaporation capacity in the Three Gorges Reservoir. Theresults show that the evapotranspiration at the various stations are consistent with each other; there is a significant decrease trend in fluctuates ofannual surface evaporation and change of annual evaporation. The annual variation is that the evapotranspiration of the upper reaches of thereservoir is small and the change gradually increases from the upstream to downstream while the surface evaporation is increasing from theupstream to downstream.