Spatiotemporal evolution and heterogeneity-driven mechanisms of land surface temperature in the Hexi Corridor

Surface temperature is a key indicator of land-air interactions and climate change. By analyzing the spatial heterogeneity of surface-temperature changes and the factors influencing this heterogeneity in arid zones, we can implement regional ecology and sustainable development. Based on MODIS (MOD11A1) data collected from 2001 to 2023, this paper analyzes the spatial and temporal characteristics of land surface temperature (LST) in the Hexi Corridor (Gansu Province, China). The analysis uses Sen Slope estimation with a Mann-Kendall nonparametric test, along with geo-detector and multi-scale geographically-weighted regression methods to reveal the trends of the influencing factors and their spatial heterogeneity. The results show that: (1) from 2001 to 2023, the surface temperature increased in 76.51% of the areas in the Hexi Corridor. The trends show obvious spatial differentiation, with cold-island enhancement in oasis areas such as Jiuquan and Dunhuang. (2) The geodetic probe results indicate an increase in particulate matter with increasing LST, which is mainly driven by potential evapotranspiration (q>0.81) and elevation (q>0.74). The interaction between these factors enhances the explanatory power of LST. (3) Multiscale geometrically weighted regression further revealed significant regional differences among the distributions of regression coefficients of the factors. Population density is associated with the “heat island effect” in urban areas and blue-green space exerts a cooling effect in most regions. PM2.5 exhibits a dual effect on temperature: its thermal impact is determined by its chemical compositio—warming when dominated by black carbon, and cooling when sulfate dominates due to the “parasol effect”. This study reveals the spatial and temporal evolution characteristics of LST and its complex driving mechanism in the arid zone, providing a scientific basis for formulating ecological environmental management and climate adaptation strategies in arid zones.