[Analysis of the Urban Water Eco-environment Protection Strategy in the Beijing-Tianjin-Hebei Region from "Three Waters" Overall Planning].

Clarifying the direction and strategy of water eco-environment protection in the Beijing-Tianjin-Hebei region is of great significance for realizing the water eco-environment protection and high-quality, coordinated development of the Beijing-Tianjin-Hebei area, as well as the goal of building a beautiful China by 2035. From the perspective of "Three Waters" overall planning, based on the urban scale of the Beijing-Tianjin-Hebei region, this study constructed six dimensions of water resources, water environment, water ecology (Three Waters), socio-economic development level, pollutant emissions, and environmental governance efforts. The water eco-environment protection strategy analysis system provided a logical framework for quantifying the current status of the water eco-environment. The ideal value was compared in each city, the PROMETHEE method was used to quantify the gap between each city and the ideal value of water eco-environment protection, and the current situation of the water eco-environment in Beijing-Tianjin-Hebei cities was evaluated. Additionally, water eco-environment protection strategies were formulated according to local conditions. The ranking of the comprehensive level of water eco-environment protection from high to low was Beijing>Tianjin>Qinhuangdao>Hengshui>Zhangjiakou>Langfang>the mean value of net flow value (Phi)>Handan>Chengde>Cangzhou>Baoding>Tangshan>Shijiazhuang>Xingtai; a large gap remained between the level and the ideal value. The hierarchical analysis showed that the advantages and disadvantages of each city's water eco-environment protection were different from dimensions to indicators, and they had the characteristics of local water eco-environment protection. Future efforts should determine the water ecological, environmental protection indicator level of each city in the Beijing-Tianjin-Hebei region, conduct a separate analysis for each city, and propose protection strategies for future development, as well as continue to help the water eco-environmental protection in the Beijing-Tianjin-Hebei region.