This study investigates the coordination of factors in the three coupled systems of water resources, economy and ecosystem. The study data were economic, social, environmental and water resource indicators of the Henan section of the Yellow River basin from 2000 to 2019. Data were analyzed using a model of coupling coordination, grey relational analysis and a combined sparrow search algorithm–back propagation (SSA-BP) prediction model. Evaluation, analysis and prediction of the water resources–economy–ecosystem complex were undertaken. The results show that: (1) the degree of coupling coordination of the water resources–economy–ecosystem complex in the Henan section of the Yellow River basin showed an increasing trend that reached 0.8105 in 2019, which indicates good coordination; (2) the water resources subsystem had the greatest influence on the overall degree of coupling coordination, followed by the economic and natural environment subsystems; and (3) the SSA-BP model predicted that the degree of coupling coordination would remain good for the next six years and reach 0.8333 in 2025. To ensure the sustainability of expected rapid economic development, Henan Province must increase the utilization efficiency of water resources, strengthen environmental protection, and coordinate development in the region.

The interconnection of water, energy, and food constitutes a complex and intricate relationship. A comprehensive index system for the water–energy–food (WEF) nexus in the Yellow River Basin (YRB) in Henan Province was formulated utilizing entropy weighting and the analytic hierarchy process. This was carried out to quantify and assess the evolution of the WEF nexus from 2006 to 2020. GeoDetector was employed to ascertain how selected factors influenced the coupled, coordinated growth of the WEF nexus. Three principal findings were revealed in this study. (1) The value of the comprehensive evaluation index of the WEF nexus increased over the study period from 0.2752 to 0.7044, with the degree of coupling coordination expanding from 0.5232 to 0.8361, indicating an overall increasing trend. (2) Significant spatial disparities across the province were detected in the degree of coupling coordination of the WEF nexus. Cities such as Kaifeng, Zhengzhou, and Luoyang had greater degrees of WEF coupling coordination compared to other cities, while Jiyuan demonstrated the least degree of coordination. (3) GeoDetector exhibited that factors like education expenditure, arable land area, and population density individually exerted a strong influence on coupling coordination; the influence of two-factor combinations heightened this effect, and nonlinear relationships between factor pairs further increased the influence. This investigation offers a conceptual structure for planning and implementing high-quality development in the YRB in Henan Province, thus serving as an essential reference for local governmental decision making.

Water and nitrogen are fundamental factors for maintaining yield stability and achieving efficient resource utilization in wheat–maize rotation systems. Based on 131 publications indexed in the Web of Science Core Collection from 2010 to 2025, this review systematically synthesizes current knowledge on how irrigation, nitrogen application, and soil management jointly regulate water–nitrogen migration and transformation processes during wheat and maize growth. The results indicate that irrigation practices influence nitrogen transformation and availability by altering the temporal and spatial distribution of soil moisture; optimized nitrogen application strategies align nitrogen release with crop demand at critical growth stages; and the use of soil amendments improves soil physicochemical and biological conditions, thereby enhancing water retention and nitrogen stability. These three management measures exhibit strong complementarity and synergistic effects. Integrating irrigation, fertilization, and soil management can not only improve wheat and maize yields but also harmonize resource use efficiency with ecological sustainability. This review highlights the potential and pathways of integrated management practices for enhancing water and nitrogen use efficiency and ensuring food security, providing theoretical support and practical guidance for developing efficient and sustainable region-specific water–nitrogen management systems.

The harmonious development between water resources, the economy, and the environment is the foundation of regional high-quality development, and the three are closely related. Based on a full analysis of the current situation of the lower Yellow River, this paper combines domestic and foreign studies, compares the framework of the relationship between water resources, the economy, and environment systems, selects 30 indicators such as average rainfall, natural population growth rate, PM2.5, etc., and establishes an evaluation model of the coupled coordination of the water resources–economy–environment system of the lower Yellow River, and then uses system dynamics to simulate and predict the degree of coupled coordination in the sub-scenarios. The conclusions are as follows: (1) The level of coordinated development in the water resources–environment system outperforms that of the water resources–economy and economy–environment systems in the cities along the lower Yellow River. (2) The coupling coordination degree of the lower reaches of the Yellow River increases from 0.5849 to 0.8209 during the period of 2006–2020, with an average annual increase of 2.62%. (3) A sub-scenario simulation for the 2006–2020 period indicated that the coordination development of the WEE system is optimal under the scenario 4 model, with the coupling coordination degree expected to reach 0.8928 in 2035, marking the advent of high-quality coordinated development. This study can provide a theoretical basis for the ecological protection and high-quality development of the Yellow River Basin.

This study aims to quantify the spatiotemporal evolution of ecosystem service value (ESV) in the Zhengzhou Metropolitan Area from 2010 to 2022. We employed an improved equivalent factor method to calculate ESV and used Geodetector analysis to identify its key driving factors. Over this 12-year period, the total ESV exhibited a spatial decreasing pattern from west to east, with farmland and forestland contributing the most to total ESV. Geodetector results across four grid scales indicate that vegetation cover (Fractional Vegetation Cover, FVC) and slope Digital Elevation Model (DEM) are the primary natural drivers; notably, the optimal model fit was achieved at finer grid scales. These findings provide a scientific basis for promoting coordinated eco-economic development and formulating conservation strategies during the urbanization process of the Zhengzhou Metropolitan Area.

Summer maize is an important grain crop in the North China Plain, but the problem of irrational application of water and fertilizer is becoming increasingly serious. Optimizing water and nitrogen management not only improves yield but also reduces water and fertilizer waste and environmental pollution. The Aquacrop model was calibrated and validated using a two-year summer maize field trial, and 16 different water and nitrogen scenarios were simulated and analyzed. In particular, the field trials were divided into 10 water–nitrogen treatments. The results showed that (1) the model has good applicability to the growth process of summer maize in the North China Plain. (2) Excessive water and nitrogen application would reduce yield by 5.6–33.7%, nitrogen bias productivity by 8.1–32.5%, and water use efficiency by 6.4–84.6%. (3) The optimal irrigation and nitrogen application program for furrow-irrigated summer maize is an irrigation quota of 360 mm in conjunction with nitrogen application of 240 kg/ha. This study provides a theoretical basis for a water-saving, fertilizer-saving, high-yield water and fertilizer management system for summer maize in the North China Plain.