Coordinated Development of Water–Energy–Food–Ecosystem Nexus in the Yellow River Basin: A Comprehensive Assessment Based on Multi-Method Integration

The Yellow River Basin serves as a critical ecological barrier and economic corridor in China, playing a pivotal role in national ecological security and sustainable development. This study develops a comprehensive evaluation framework grounded in the Water–Energy–Food–Ecosystem (WEFE) nexus, employing 25 indicators across nine provinces and autonomous regions over the period 2000–2023. Utilizing a multi-method approach—including the entropy weight method, coupling coordination degree model, center of gravity migration analysis, principal component analysis, and obstacle factor diagnosis—the research investigates the coordinated development and dynamic interactions among the WEFE subsystems. Key findings include: (1) the calculated weights of the water, energy, food, and ecological subsystems were 0.3126, 0.1957, 0.1692, and 0.3225, respectively, indicating that ecological and water subsystems exert the greatest influence; (2) distinct growth patterns among subsystems, with the energy subsystem exhibiting the fastest growth rate (212%) and the water subsystem the slowest (4%); (3) a steady improvement in the overall coordination degree of the WEFE system, rising from 0.417 in 2000 to 0.583 in 2023—a 39.8% increase—with Henan (0.739) and Inner Mongolia (0.715) achieving the highest coordination levels in 2023, while Qinghai (0.434) and Ningxia (0.417) remained near imbalance thresholds; (4) complex spatial dynamics reflected by cumulative center of gravity migration distances of 678.2 km (water), 204.9 km (energy), 143.3 km (food), and 310.9 km (ecology) over the study period; and (5) identification of per capita water resources as the principal limiting factor to coordinated WEFE development, with an obstacle degree of 0.1205 in 2023, underscoring persistent water scarcity challenges. This integrated framework advances WEFE nexus analysis and provides robust, evidence-based insights to inform regional policy and resource management strategies.