The Reservoir Sustainability Paradox: Divergent Pathways and Systemic Imbalances Revealed

Reservoir basins globally face an intensifying sustainability paradox: balancing economic growth, social welfare, and environmental protection often triggers systemic trade-offs. However, comprehensive assessments revealing these internal imbalances remain scarce, hindering targeted governance. To address this gap, this paper developed a multidimensional framework of Ecological development benefits, integrating Entropy-Weighted AHP and Fuzzy Mathematics. Applying this to 2015–2022 data from the Sanmenxia Reservoir in the Yellow River Basin of China revealed three development paradoxes: Protection-prioritized regions face diminishing returns; growth-driven regions accumulate ecological deficits; and environmentally stagnant regions decline in resilience. Critically, no optimal pathway exists—all subregions exhibited significant imbalances despite aggregate ecological improvements, and policy shocks (e.g., COVID-19, new environmental laws) amplified disparities, exposing institutional fragmentation. Based on the research findings, policy recommendations are proposed for green financing mechanisms, adaptive governance, and region-centered protection, which directly advance SDGs 6 (water security), 8 (inclusive growth), and 13 (climate action), offering a transferable analytical framework for basins like the Mekong and Nile, which are confronting similar paradoxes.