Impact of soil salinity changes on the evolution of evapotranspiration driving mechanisms

jabbrv-ltwa-all.ldf jabbrv-ltwa-en.ldf Understanding soil salinization’s impact on evapotranspiration ( ET ) is crucial for water management and ecological restoration in arid and semi-arid regions. This study quantifies the impact of soil salinization on ET in the Lower Yellow River Irrigation District from 2000 to 2016 using the PML-V2, Global Soil Salinity Map, and an innovative soil salinity transition matrix. A grid-based normalized multiple linear regression is used to identify the dominant factors influencing ET , and effects of soil salinization variation on ET ’s driving mechanisms was assessed. Results show that soil salinization is mainly slight, intensifying in the south and alleviating in the north. ET decreases from southwest to northeast, while a general increase trend in ET is observed across all 15 sub-irrigation districts. ET increases with precipitation, temperature, and NDVI , but is negatively influenced by soil moisture. Increased salinization suppresses ET while strengthening precipitation and NDVI ’s positive effects, shifting the driving mechanism from ”temperature-soil moisture driven” to ”precipitation- NDVI driven.” Reduced salinization strengthens temperature’s effect and amplifies soil moisture’s negative impact, reverting to a ”temperature-soil moisture driven” mechanism. The study also identifies declining soil moisture alongside increasing ET , emphasizing the need to address soil salinization. These findings provide insights into salinization’s regulation of ET and support sustainable water management and ecological conservation.