The impact of environmental regulation on water resources carrying capacity in the Yangtze River Economic Belt

ABSTRACT Enhancing environmental regulation (ER) is a key strategy for improving the carrying capacity of water resources. This study employs panel data from 11 provinces and cities within the Yangtze River Economic Belt, spanning from 2008 to 2022, to calculate the carrying capacity of water resources using an enhanced TOPSIS model. It further examines the threshold effect and spatial spillover effect of ER on water resources carrying capacity (WRCC) through the construction of panel threshold models and spatial econometric models, respectively. Findings indicate a stable growth trend in the carrying capacity of water resources across the Yangtze River Economic Belt, with the upstream region typically exhibiting a higher capacity than both the midstream and downstream regions. ER positively impacts WRCC, demonstrating a single threshold effect. Nonetheless, the positive effect of ER on WRCC experiences diminishing marginal returns as industrial structure upgrades. While strengthening ER positively influences the carrying capacity of water resources in local areas, it exerts a negative spatial spillover effect on neighboring regions. In light of these findings, implementing differentiated ER, optimizing industrial structure and collaborative policies and promoting technological innovation are vital for fostering WRCC.