Spatial heterogeneity analysis of climate driving factors for spatiotemporal changes in potential evapotranspiration based on Multi‐Scale Geographically Weighted Regression and Geographical Detector

Study region: Hexi Corridor, a representative arid and semi-arid inland region, northwestern China. Study focus: To overcome the limitations of previous studies in terms of the spatial heterogeneity of the driving factors influencing potential evapotranspiration (PET) changes, and to address the issue of spatial non-stationarity of PET caused by climatic factors, this study exploratively introduced the Geographical Detector (GD) and Multi-Scale Geographically Weighted Regression (MGWR). We analyzed the spatial-temporal distribution pattern of PET in the Hexi Corridor region, and revealed the spatial heterogeneity distribution characteristics of the driving factors at the grid cell scale. At the same time, important climatic factors with significant influence were identified, as well as the dual-factor driving mechanism. New hydrological insights for the region: PET showed an increasing trend from southeast to northwest, with a significant increase accounting for 18.08%, a non-significant increase accounting for 57.86%, and a non-significant decrease accounting for 24.06%. In most areas of the Hexi Corridor, PET showed an increasing trend (75.94%). The precipitation and wind speed are the main factors causing spatial variations in PET. Any interaction between two factors is manifested as bi-variable enhance and nonlinear-enhance. The synergy of the two factors can enhance the explanatory power of a single factor for the spatial differentiation of PET. The influence of elevation on PET has a global characteristic, while the influence of meteorological factors has a stronger local dependence. The PET in the northwest of the Hexi Corridor is significantly affected by wind speed and temperature, while in the central and eastern parts, it is significantly inhibited by precipitation and relative humidity. In the southeast, PET is positively promoted by the sunshine duration. In most areas of the Hexi Corridor (86.21%), PET will show a continuous increasing trend in the future, while in some local areas in the west and east (13.79%), there will be a continuous decreasing trend.