The acceleration of urbanization and climate change has increasingly impacted the health level of urban dual water cycles. In order to accurately evaluate the health status of urban water cycles, the evaluation system covers four standard layers of water ecology, water abundance, water quality and water use, including 19 basic indicators such as water storage change and annual average precipitation. Three-scale AHP and EFAST algorithms are adopted to set the criterion and index layer weights. Water-cycle health assessment models are based on the improved TOPSIS model. The model evaluated Zhengzhou’s water cycle health from 2011 to 2021. We compared the TOPSIS model and FCE method to ensure the scientific objectivity of the evaluation results. The evaluation results indicated that the water cycle in Zhengzhou City improved annually, and the relative progress in 2020 was 0.567 in a sub-health state. The eco-environmental water demand, green coverage rate of the built district, water resources amount, and industry’s water consumption per unit of value added (CNY 10,000) were the major obstacles. These four factors have preponderantly influenced Zhengzhou City’s water cycle health. Our research results provide scientific reference for Zhengzhou to achieve a healthy urban water cycle and regional sustainable development.

Both the natural and social water cycles form part of the regional water cycle, and the assessment of the health of the social water cycle provides useful recommendations for resource allocation, urban planning, and development. The Zheng-Bian-Luo region (Zhengzhou, Kaifeng, Luoyang city cluster in China) is used as an example in this study. The three-level “goal criterion index” is used to develop a water cycle index system based on deeper knowledge of the notion of the social water cycle. The system has four criterion layers that measure water quantity, utility, quality, and ecology, in addition to 22 index levels regarding the total water resources and drinking water compliance rate. By using this as a foundation, the minimum information entropy principle was applied to couple AHP (Analytic Hierarchy Process) and EFAST (Extended Fourier Amplitude Sensitivity Analysis) in order to calculate the comprehensive weights of the evaluation indicators and build a VIKOR (Intuitionistic Fuzzy Multi-attribute Decision Making Method) model of the relative preference relationship of the fused weights. This model was then compared to the conventional VIKOR model and the FCE (Fuzzy Comprehensive Evaluation Method) method in order to reflect on the objectivity of the evaluation results. The primary barriers preventing the improvement of water cycle health in the Zheng-Bian-Luo region were determined in this study by using the barrier degree model. The findings demonstrate that over the past 11 years, the overall water cycle health in the Zheng-Bian-Luo region has developed toward a healthy trend and that the water cycle health level in the region has gradually improved from the initial sub-pathological state to a healthy state. The results also demonstrate compliance with domestic drinking water sources, comprehensive water consumption per capita, the water consumption of CNY 10,000 of industrial-added value, the water consumption of CNY 10,000 of GDP, and the water consumption of CNY 10,000 for water. The primary barrier to the Zheng-Bian-Luo region’s improvement in water health is the water consumption ratio. The findings of this study can serve as a scientific foundation for creating a balanced urban water cycle and achieving long-term development in the area.

Studying the spatio-temporal evolution characteristics of the “water–carbon–ecological” footprint and the decoupling status of its main driving factors is of paramount importance for achieving sustainable development in society. Based on quantifying the footprint family, this study constructs an integrated driving factor analysis model of “Kaya–LMDI–Tapio”, screens the main driving factors influencing the footprint family, and conducts decoupling analysis. The research results indicate that: (1) The water, carbon, and ecological footprints of the Yangtze River Economic Belt from 2002 to 2017 were 1534.265 billion cubic meters, 61,672.89 million hectares, and 45,528.76 million hectares, respectively. (2) The main driving factors for water, carbon, and ecological footprints were economic effect factors, agricultural production scale factors, and economic effect factors. (3) During the research period, the decoupling trends between the water, carbon, and ecological footprints and their main driving factors presented a transformation from a weak decoupling state to a strong decoupling state, the decoupling index value decreased initially and then increased, and the decoupling index value showed a downward trend. These findings provide a quantitative basis for the formulation of differentiated basin management policies, indicating that, through the collaborative promotion of technological innovation and institutional innovation, the leap from relative decoupling to absolute decoupling can be achieved, which has important reference value for the sustainable development governance of global river basins.

Driven by global population growth and resource shortages, the coupled and coordinated development of the “Water-Carbon-Ecology” (W-C-E) nexus has emerged as a crucial factor for sustainable societal development. This study constructs a multidimensional evaluation model for the W-C-E system in the eleven provinces and municipalities of the Yangtze River Economic Belt (YEB), encompassing the richness of individual systems, the coordination between dual systems, and the robustness of the tertiary system. We propose the “W-C-E Nexus Index” (WCENI) to analyze the coupling and coordination levels among the W-C-E systems in these regions from a bottom-up perspective. Utilizing the obstacle degree model and geographical detector model, we explore the impact of key indicators on the coupled and coordinated development of the W-C-E system. The findings reveal the following: (1) The coordination index and robustness index among the three W-C-E subsystems have increased significantly, while the richness index of individual subsystems varies widely among the YEB. (2) During the study period, the WCENI for the YEB rose from 0.351 to 0.391, indicating an overall upward trend in the coupling and coordination among the W-C-E subsystems. Jiangsu recorded the highest average WCENI value of 0.445, topping the list of the eleven regions. (3) The interaction between pairs of driving factors exceeds the influence of any single factor, with per capita water consumption emerging as the primary driver for the coupled and coordinated development of the W-C-E nexus in the YEB, with an average obstacle degree of 12.05%. These findings provide a theoretical basis for regional coordinated management and sustainable development.

The regional water cycle reflects both natural and social processes. The health of the regional water cycle is of great significance to the sustainable development of human beings. Focusing on the nine provinces and regions in the Yellow River Basin, this study utilized the DPSIRM model, including 21 basic indicators. In this paper, according to the principle of minimum information entropy, the three-scale AHP and EFAST algorithms were combined and weighted, and water cycle health status in the nine provinces and regions was evaluated based on the hook trapezoidal fuzzy TOPSIS model. Moreover, the traditional TOPSIS model was compared with the FCE method so as to evaluate the objectivity of the results. The obstacle degree model was introduced to obtain the main obstacle factors affecting the improvement of water circulation health in the nine provinces and regions. The results show that the water circulation health status in the nine provinces and regions is tending towards health, coordination, and balance. Water consumption in the ecological environment, water consumption per CNY 10,000 of GDP and forest coverage rate are the key factors that influence the improvement of water circulation health in the nine provinces and regions. The research results herein provide a scientific reference for the nine provinces and regions to achieve a healthy urban water cycle and regional sustainable development.