Identification of driving mechanisms of actual evapotranspiration in the Yiluo River Basin based on structural equation modeling  

作　　者：Shu Xu Tianling Qin Jie Lu Shanshan Liu Jun Hou Jianming Feng Wei Li Hanxiao Liu Sintayehu A.Abebe 

机构地区：[1]State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,No.1 Fuxing Road,Haidian District,Beijing 100038,China [2]School of Resources and Environment,Anqing Normal University,Anqing 246133,China [3]Hydraulic and Water Resources Engineering Department,Debre Markos University Institute of Technology,Debre Markos,Ethiopia

出　　处：《Ecological Processes》2024年第4期109-124,共16页生态过程(英文)

基　　金：supported by the National Science Fund Project under Grant(No.52342905);the National Science Fund Project under Grant(No.52130907);the Major Science and Technology Project of the Ministry of Water Resources of the People’s Republic of China under Grant(SKS-2022033).

摘　　要：Background Actual evapotranspiration(ETa)is a crucial aspect of the hydrological cycle.It serves as a vital link between the soil–vegetation–atmosphere continuum.Quantifying the leading factors of regional ETa change and revealing the multi-factor compound driving mechanism of ETa evolution is necessary.Structural equation modeling(SEM)has been widely used to study the structural relationships between variables in large-scale areas.However,there is an urgent need for more in-depth exploration of these complex relationships at the grid scale.Therefore,the Yiluo River Basin,a representative area of soil and water conservation engineering demonstration in the Loess Plateau,was selected as the study area,and the SEM at the basin scale and grid-scale were constructed to carry out the research.Results The data indicate that ETa decreased at 1.97 mm per year at the watershed scale from 1982 to 2020.Climate change had the greatest impact on the change of ETa in the watershed,with a total impact coefcient of over 0.9.The direct impact of climate change on ETa increased by 0.571 from 1982–1992 to 1993–2020.The direct impact coefcients of vegetation cover and soil moisture decreased by 0.402 and 0.102,respectively,while the impact coeffcient of the water body factors increased by 0.096.At the scale of individual grid cells,the ETa in the watershed was afected by changes in watershed climate,vegetation,and soil moisture,with contributions ranging from−0.31 to 0.22,−1.09 to−0.08,and 0.61 to 0.90,respectively.Spatially,vegetation and soil moisture had a stronger impact on ETa in the upstream area,while climate change had a negative efect,and the downstream region had the opposite efect.Furthermore,the regulatory impact of large reservoirs mitigated the response of water surface evaporation to climate change in the upstream region.Conclusions The application of SEM at diferent spatial and temporal scales has efectively quantifed the driving mechanisms behind actual evapotranspiration in the Yiluo River Basin,while

关 键 词：EVAPOTRANSPIRATION Structural equation modeling Spatial grid Driving mechanism identification 

分 类 号：P333.1[天文地球—水文科学]