利用GRACE重力卫星观测研究近7年云南省水储量变化

基于高斯平滑法对2002年8月-2010年6月共计95个月的GRACE RL04数据反演得到云南省水储量数据,结合云南省122个气象台站的月降水、月气温资料,利用趋势分析方法研究了云南省近7年来的水储量时空变化特征。结果表明,水储量的月变幅变化过程与降水的月变化过程具有一致性,从水储量变幅可以反映出云南省2010年特大干旱事件和2005年比较严重的初夏干旱事件。云南省西北部近7年来降水减少,气温升高使得蒸散发量增加,导致该区域的水储量呈减少趋势,但是东南部受降水增加以及人类蓄水等工程的影响,水储量呈增加趋势。同一区域水储量的年内变化趋势在不同季节有所差异,除夏季有效降水量变化趋势与水储量变化趋势不一致之外,其他季节的水储量与有效降水变化趋势一致。

Spatial and Temporal Variation of Water Storage in Recent Seven Years from GRACE in Yunnan Province

The GRACE RL04 dates from August 2002 to June 2010 were selected to compute the water storage of Yunnan Province in recent 7 years using Gaussian smoothing method.Combined with monthly rainfall and temperature data of 122 national weather stations and using trend analysis method,the spatial and temporal character of Yunnan Province water storage were analyzed.The result showed that the variation of monthly water storage and precipitation were consistent.The variation of water storage also mirrored the extreme drought event in 2010 and early summer drought in 2005.Higher temperatures increased evapotranspiration and decreased rainfall had led to the decreasing trend of water storage in the Northwestern of Yunnan.However,the impact of increased precipitation and human water storage engineering caused the water storage increased in the Southeastern.Lastly,the changed trend had the difference in different season at the same region.Besides in summer,the trend of effective precipitation was disagreed with water storage,the variation tendency of water storage was consistent with effective precipitation.