摘要
为了更好地了解长江中下游6个子流域蒸散发量时空演变特征,以及气候和下垫面因子改变对蒸散发量变化的影响,基于GRACE重力卫星观测数据和水量平衡法重建了长江中下游6个子流域实际蒸散发ET序列,评估并融合了3种ET数据集,获得1992—2015年高精度的逐月蒸散发量,分析了6个子流域蒸散发量年值和季节值的变化趋势,引入土地利用程度综合指数La,基于通径分析法定量评估了气候和下垫面因子对各子流域蒸散发量变化的直接和间接影响。结果表明:①3种数据集在长江中下游流域的适用性较好,基于最小二乘权重法的数据融合方法减小了ETrecon与ETNOAH、ETGLEAM的平均差和均方根误差,减小了ETNOAH、ETCR的标准差。②长江中下游流域多年平均蒸散发量为728.7 mm,空间上自西北向东南递增;6个子流域不同季节的蒸散发量均呈升高趋势,其中春、夏季的增幅最大。③各子流域年蒸散发量增加主要由La增强和气温升高所致,气温、La和植被覆盖率等要素的间接作用致使太湖流域风速降低对蒸散发量的影响从正向变为负向。④气温升高促进了NDVI对6个子流域春、夏季蒸散发量增加的正向效应,太湖流域、长江中游和下游干流区秋、冬季降水的增加削弱了辐射降低对蒸散发量变化的作用,而风速上升是洞庭湖流域、中游干流区冬季蒸散发量微弱增加的主导因素。研究结果将为长江中下游流域水资源管理、干旱预测和生态功能评估等研究提供理论基础与科学依据。
In order to better understand the spatial and temporal evapotranspiration(ET)evolution characteristics of the six sub-basins in the middle and lower reaches of the Yangtze River,as well as the impacts of the changes in climate and subsurface factors on the changes in ET,the actual ET sequences of the six sub-basins in the middle and lower reaches of the Yangtze River were reconstructed based on the GRACE gravity satellite observation data and the water balance method.Three ET datasets were evaluated and merged to obtain high-precision monthly ET from 1992 to 2015.The trend of annual and seasonal ET in 6 sub-basins was analyzed,and the comprehensive index of land use degree(La)was introduced.Based on path analysis,the direct and indirect effects of climate and underlying surface factors on the change of ET in each sub-basin were quantitatively evaluated.The results are as follows.Firstly,the applicability of the three datasets in the middle and lower reaches of the Yangtze River Basin is better,and the data fusion method based on the least-squares weighting method reduces the mean difference and root-mean-square error of ETrecon and ETNOAH and ETGLEAM,and reduces the standard deviation of ETNOAH and ETCR.Secondly,the average ET in the middle and lower reaches of the Yangtze River Basin is 728.7 mm,increasing spatially from northwest to southeast.The ET of the six sub-basins showed an increasing trend in different seasons,and the increase was the largest in spring and summer.Thirdly,the increase of annual ET in each sub-basin was mainly caused by the enhancement of La and the increase of air temperature,and the indirect effects of air temperature,La and vegetation cover caused the effect of the decrease of wind speed on ET in the Taihu Lake basin to change from positive to negative.Fourthly,the increase of temperature promoted the positive effect of NDVI on the increase of EV in spring and summer in 6 sub-basins.The increase of precipitation in autumn and winter in the Taihu Lake basin,the middle and lower reaches
作者
曹新
邢万秋
傅巧妮
杨丽琳
CAO Xin;XING Wanqiu;FU Qiaoni;YANG Lilin(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China)
出处
《华北水利水电大学学报（自然科学版）》
北大核心
2024年第4期36-46,55,共12页
Journal of North China University of Water Resources and Electric Power：Natural Science Edition
基金
国家自然科学基金联合基金项目(U2240218)
中央高校基本科研业务费项目(B220202034)。
关键词
实际蒸散发
下垫面
气候变化
驱动机制
长江中下游流域
actual evapotranspiration
underlying surface
climate change
driving mechanism
the middle and lower reaches of the Yangtze River Basin
