Research on Regional Disparities, Dynamic Evolution, and Influencing Factors of Water Environment Governance Efficiency in China

To investigate the effectiveness of water environment governance in China, this study employs the Super-SBM model to measure the WEGE (water environment governance efficiency) of 283 prefecture-level cities in China from 2013 to 2022. Multidimensional decomposition is conducted using the Dagum Gini coefficient, kernel density estimation, convergence models, and the Tobit model. The findings reveal the following: (1) China's WEGE is generally at a low-efficiency development stage, exhibiting a pattern of "western regions > central regions > eastern regions". WEGE evolves from "scattered distribution" to "multi-center aggregation". (2) The overall Gini coefficient for WEGE in China is relatively low, with an average of 0.120. Intra-group differences and transvariation intensity are the primary sources of regional disparities. (3) The country and the three major regions exhibit right-tailed and multi-polar phenomena. (4) sigma-convergence is observed exclusively in the eastern area, whereas both absolute and conditional beta-convergence are evident throughout the country as well as within the three major regional divisions. (5) Government intervention has a significant positive impact on WEGE, while artificial intelligence, spatial agglomeration, and industrial structure upgrading exert negative effects on WEGE. Therefore, it is urgent to pay attention to the regional differences in WEGE and implement practical measures for collaborative water environment governance.