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

作者：Shu Xu, Qin Tianling, Jie Lu, Shanshan Liu, Jun Hou, Jianming Feng, Wei Li, Hanxiao Liu, Sintayehu A. Abebe · 发表于：Ecological Processes · 年份：2024 · DOI：10.1186/s13717-024-00551-3 · 被引用次数：9 · 研究领域：Hydrology and Watershed Management Studies、Environmental and Agricultural Sciences、Plant Water Relations and Carbon Dynamics

Abstract 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 coefficient 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 coefficients of vegetation cover and soil moisture decreased by 0.402 and 0.102, respectively, while the impact coefficient of the water body factors increased by 0.096. At the scale of individual grid cells, the ETa in the watershed was affected by changes in watershed climate, vegetation, and soil moisture, with contributions ranging ...