How Integrated Are Water and Food Systems in China? Assessing Coupling Mechanisms and Geographic Disparities

Water resources are of vital importance to human survival and development. This study systematically analyzed the coupling coordination mechanism between China’s food security (FS) and water resource management (WRM) from 2010 to 2022 using the TOPSIS model, Dagum Gini coefficient, coupling coordination model, and fixed effects regression model. The results indicate that FS exhibited a “U-shaped” evolution: an average annual decline of 1.4% before 2017 followed by recovery to 2.39% due to policy optimization and technological upgrades, though significant regional disparities persisted with 15 provinces maintaining ecological vulnerability scores below 0.3. WRM showed an average annual increase of 1.33%, later accelerating to 1.76% driven by projects like the South-to-North Water Diversion Project, which significantly improved 28 provinces. The FS-WRM coupling coordination degree escalated from mild imbalance to near imbalance, forming a spatial pattern of “central region leading–northeast following–eastern fluctuation–western catching up”, with 10 provinces reaching barely coordinated levels in 2022. The study reveals that policy support, infrastructure development, technological innovation, and management model transformation are key influencing factors for FS-WRM coupling coordination.