Coupling Coordination and Driving Mechanisms of the Agricultural Water–Energy–Food System in the Lower Yellow River Basin

This study aims to quantify and explain the coupling coordination dynamics of the agricultural water–energy–food (WEF) nexus in 40 Yellow River–diverted irrigation districts located in the lower reaches of the Yellow River during 2000–2020. Based on the identification of key system elements, the coupling coordination degree of the WEF nexus was measured to characterize its integrated development level. Drawing on synergetics theory, a hybrid analytical framework combining geographically and temporally weighted regression (GTWR) and the XGBoost-SHAP model was employed to reveal the internal synergistic evolution processes and external driving mechanisms while accounting for spatiotemporal heterogeneity and nonlinear effects.

The results show that the coupling coordination of the WEF nexus exhibited an overall steady upward trend, characterized by a spatiotemporal evolution pattern of continuous improvement, stage-specific fluctuations, and overall convergence. Temporally, the coordination degree transitioned from slow growth to rapid improvement, while spatial disparities among irrigation districts gradually narrowed, accompanied by increasingly pronounced spatial clustering effects. The nighttime light index and the proportion of cultivated land exerted long-term and stable positive impacts on coupling coordination, whereas average temperature and population density acted as primary constraints; precipitation, NDVI, grassland proportion, and water area proportion played secondary roles. Significant threshold effects were identified for all driving factors, indicating that moderate economic development, suitable climatic conditions, and a rational land-use structure are critical for maintaining high-level coordination, beyond which coordination declines rapidly.

Furthermore, scenario-based simulations incorporating climate change and technological progress were conducted using random forest models to explore future evolution trajectories. The coupling coordination degree under the SSP245 baseline scenario consistently outperformed that under SSP585, suggesting that climate stress associated with high-emission pathways negatively affects system coordination. Among individual technological measures, water-saving practices were identified as the most effective single intervention.These findings provide a quantitative basis for scenario regulation, zonal management, and the optimization of sustainable development pathways in Yellow River–diverted irrigation districts.