Coupling of water-land resources and water governance in China’s Poyang Lake Urban Agglomeration

The scientific and efficient use of water and land resources is an inevitable requirement for China’s ecological civilization and achieve high-quality development. Investigating the spatiotemporal evolution of the utilisation efficiency of water and land resources in the Poyang Lake Urban Agglomeration, as well as the factors influencing water environment governance, can provide strategic support for the coordinated development of these resources in this urban agglomeration. This study examines the non-desired output Super-SBM model and the coupling coordination degree model to examine the spatiotemporal evolution of water and land resource utilization efficiency in the Poyang Lake Urban Agglomeration from 2009 to 2022. The results show that the efficiency of the utilization of water and land resources increased with spatial heterogeneity. The coupling coordination degree evolved from impending imbalance to medium-level coordination, with a spatial pattern of “high in the east and low in the west”. Urbanization, land resource utilization efficiency, and foreign investment positively affect water resource utilization efficiency, while industrial structure, agricultural mechanization, and economic development level have negative impacts. The negative effect of R&D expenditure and the positive effect of grade highway construction have a lag effect. Overall, although the mean coupling-coordination degree improved, it remained between “marginal” and “primary” coordination, indicating modest rather than high-quality synergy. This study therefore propose efficiency-based zoning and cross-city spillover compensation as replicable tools for other lake-type urban agglomerations.