Coupled Spatial–Temporal Evolution and Influencing Factors of Chemical Industry Development and Water Environment in Yangtze River Economic Belt

Revealing the coordinated correlation between chemical industry development and the water environment is essential for promoting high-quality development in the Yangtze River Economic Belt. Based on the data in the Yangtze River Economic Belt from 2011 to 2021, this study explores the spatial–temporal evolution and influencing factors of the coupled coordination between chemical industry development and the water environment by using the global entropy method, a coupling coordination model, and the Tobit model. The results indicate a general upward trend in the comprehensive indices of chemical industry development and water environment systems, albeit with distinct spatial patterns. A mismatch between the two systems is observed in terms of spatial distribution. Regarding the coupling coordination degree, the relationship shows an upward trend, primarily at a mild-to-moderate coupling stage, exhibiting a spatial pattern of “downstream > midstream > upstream”. Moreover, a trend of increasing coordination and narrowing disparities between high- and low-level regions can be observed. The model results suggest that environmental regulation, economic development, government capacity, and urbanization play a crucial role in promoting the coupled development of the chemical industry and the water environment. However, openness to external markets may not enhance coupled coordination. These findings may provide policy guidance for the development status of two subsystems in other locations.