Abstract: The Hexi Corridor is located in an arid and ecologically fragile region. Tourism development in this area benefits from Silk Road cultural resources and major transportation corridors, but is simultaneously constrained by limited ecological carrying capacity and high resource sensitivity. Taking scenic spots above 4A-level in the Hexi Corridor as the study objects, based on an improved spatio-temporal utility approach, we constructed an integrated accessibility index from three dimensions, namely attractiveness, road network time, and travel time. By integrating random forest-SHAP analysis with multiscale geographically weighted regression (MGWR), we systematically identified the dominant factors influencing tourism accessibility and their spatial heterogeneity mechanisms. The results showed that the overall accessibility of scenic spots in the Hexi Corridor was at a medium-to-low level (accessibility values ranging from 0.03 to 1.09), and exhibited a clear “corridor concentration-peripheral attenuation” spatial pattern, with high-value areas being continuously clustered along the Lanzhou-Xinjiang Railway and the Lianyun-gang-Khorgos corridor. Attractiveness and road network time were the key determinants of accessibility. The scenic spots exhibited differentiated “attractiveness-accessibility” combinations. High-attractiveness and high-accessibility scenic spots were mainly distributed in nodal areas with favorable transport conditions and concentrated tourism resources. The accessibility formation mechanism demonstrated significant spatial heterogeneity. Improved service facilities had a stable promoting effect. Transportation costs (measured in driving time) showed a negative impact, which was more pronounced in the western segment. Slope generally had a negative effect. The distance to the nearest water system had a significant positive effect in the western and mountainous areas but weaker explanatory power in leisure-oriented attractions near cities such as Zhangye, Ganzhou, Wuwei, and Jinchang. The findings provide a scientific basis for optimizing transportation and zoning management in the Hexi Corridor tourism system.

Key words: scenic accessibility, spatio-temporal utility, random forest, multiscale geographically weighted regression (MGWR), arid ecological zone, Hexi Corridor