The study of water resources carrying capacity is a crucial aspect of water resources ecological security research. To account for the interplay between regional natural conditions and economic and social factors, a natural–economic–social–environmental evaluation index system is established within the framework of water resources. The comprehensive index of water resources carrying capacity in Anhui Province is then calculated using the entropy weight method and CRITIC model. Spatial kernel density and Dagum analysis are employed to analyze the results. The findings indicate that (1) the overall water resources carrying capacity of Anhui Province has exhibited an upward trend from 2003 to 2021, with the overall index of water resources carrying capacity increasing from 0.34 to 0.49. (2) The presence of water resources carrying capacity polarization in Anhui Province is evident, although this trend has been diminishing in recent years. (3) The Gini coefficient of water resources carrying capacity in Anhui Province first increases and then decreases, with the Gini coefficient between groups being more pronounced than the Gini coefficient within groups. (4) Geospatial factors play a significant role in shaping the future spatial distribution of water resources carrying capacity in Anhui Province. Additionally, the interaction of water resources carrying capacity among neighboring areas contributes to the reduction of differences between water resources carrying capacity in different regions in the future.

Considering the regional economic and social characteristics and high-quality development goals, this paper improves the calculation method of green efficiency of water resources and adopts the SBM-DEA model to calculate the green efficiency of water resources in 35 cities of 4 provinces in the Huaihe River Basin. The results show that (1) the green efficiency of water resources in the Huaihe River Basin decreased first and then increased from 2011 to 2020. (2) In terms of spatial distribution, the provincial-level divisions of green efficiency of water resources in the Huaihe River Basin from high to low are Shandong, Henan, Jiangsu, and Anhui. The elliptical area of green efficiency of water resources keeps expanding, and the efficiency value radiates outward along ‘Yangzhou-Zhengzhou’. (3) At the level of total-factor productivity decomposition, TC (technological change) has a more noticeable impact on factors than EC (efficiency change). TC scale technology changes mainly come from the improvement of MATC (magnitude technical change). (4) Industrial output value has a positive driving effect on the green efficiency of water resources. Government participation, resource endowment, and economic growth rate reflect China's current incongruity between economic development and water resources green efficiency improvement.

Ecological compensation is an effective way to alleviate watershed water ecological management. Considering the behavior of public participation, this paper constructs a tripartite evolutionary game model of the public, enterprises, and local governments, analyzes the evolutionary stability of the strategic choice of each participant, and discusses the influence of various factors on the strategic choice of the three parties. Combined with regional data, Matlab R2018b is used to simulate and analyze the evolution trend of each subject strategy in the Huaihe River Basin under different situations. The study found that: (1) The government's increase in rewards and punishments has significantly promoted public participation and enterprises' active governance of pollution, but increasing rewards and punishments are not conducive to local governments' own performance of regulatory responsibilities. (2) Increasing the amount of compensation and incentives is an effective way to promote public participation. (3) The sum of reputation gains, reputation losses, and rewards and punishments is greater than the difference between the additional benefits of negative governance and the cost of corporate governance, so as to ensure that enterprises actively control pollution.