As an important tributary of the Yellow River， the ecological status of the Weihe River Basin plays a significant role in regional sustainable development. This study employed the remote sensing ecological index （RSEI）， developed on the Google Earth Engine （GEE） platform， to comprehensively analyze the spatial and temporal variations in ecological status of the Weihe River Basin from 2000 to 2024， along with its underlying drivers. Methods including Theil-Sen trend analysis， Mann-Kendall test， Hurst exponent， and coefficients of variation were used to examine these changes. Additionally， the eXtreme Gradient Boosting （XGBoost） model， enhanced with SHapley Additive exPlanations （SHAP） values， was used to identify and elucidate the primary factors influencing the spatial heterogeneity of ecological status. Over the studied period， the RSEI of the Weihe River Basin is projected to increase from 0.37 to 0.53， representing an initial rise followed by stabilization. The spatial distribution shows that the ecological quality is higher in the southeast and edges， and lower in the northwest and center， with the ecological backbone formed along the northern foot of the Qinling Mountains. Meanwhile， ecological quality in the Guanzhong urban agglomeration has deteriorated. The analysis reveals a 27.4% reduction in areas of poor ecological quality， expansion of medium-quality areas， and a slow growth in high-quality areas， indicating that ecological restoration is approaching a bottleneck. Predictions suggest that 72.7% of the basin will continue to show improvements， whereas 24.4%-particularly in the mining areas of upper Jinghe River and the western expansion zones of the metropolitan area-face ongoing degradation risks. High volatility is evident in 59.3% of the basin. The spatial heterogeneity of RSEI in the Weihe River Basin is the result of the interaction of multiple factors， and there are complex synergistic and antagonistic relationships between the factors， which are driven by the dual combination of “climate mastery and anthropogenic amplification”： climatic factors ［actual evapotranspiration （AET）， land surface temperature （LST）， potential evapotranspiration （PET）， temperature （TMP）， precipitation （PRE）］ affect RSEI through the water-heat balance， of which precipitation is the key regulator of the negative effect of PET， and 20-25 ℃ is the optimal temperature window for water-heat synergy； AET and LST promote positive synergy within a moderate temperature range； and PET and PRE produce negative antagonism in areas with sufficient precipitation. At the same time where population density exceeds 600 persons·km-2， urbanisation triggers ecological degradation through the heat island effect （amplifying LST） and surface hardening （weakening PRE infiltration）. The methodologies and findings of this study provide a detailed understanding and ongoing monitoring of the dynamic evolution of RSEI in the Weihe River Basin amidst climate and population changes. This research offers a scientific foundation for the ecological protection， restoration， and sound ecological development of the Yellow River Basin.
