Spatio-Temporal Evolution and Driving Factors of Eco-Environmental Response to Land Use Transformation in China’s Southern Hilly Area During 2000–2020

Hilly areas serve as critical ecological barriers yet face developmental challenges, drawing increasing attention to how land use transformation affects eco-environmental quality (EEQ). Systematic studies on EEQ drivers in complex terrains remain limited, particularly regarding nonlinear and interactive effects. This study examines Zhejiang’s hilly area—typical of southern China’s hills—using land use data from 2000, 2010, and 2020. Methods including land use transfer matrix, EEQI, hotspot analysis, and XGBoost-SHAP were applied to assess impacts and quantify drivers. Results show a slight but consistent decline in EEQ index (EEQI) (0.7635 to 0.7472), driven primarily by rapid built-up land (BL) expansion (276.41% increase). NDVI was the most influential factor (SHAP: 0.1226, >59%), followed by GDP per unit area and temperature. NDVI showed a threshold effect (>0.65 strengthens benefit), and strong interaction with per capita GDP. A slope-vegetation coupling mechanism was identified: on slopes > 30°, high NDVI significantly amplifies EEQ improvement, highlighting the importance of vegetation conservation on steep slopes. These findings provide a scientific basis for targeted land management in hilly regions of southern China and similar areas.