Coupling assessment for the water-economy-ecology nexus in Western China

The coupling development of water, economy, and ecology is an important driver of sustainable development. The assessment of the spatial distribution and development process of the regional water-economy-ecology (WEE) nexus is the basis of regional sustainable development. This study constructs a comprehensive evaluation model to explore the coupling coordination relationship of the WEE nexus in Western China, and then the grey prediction GM (1, 1) model is applied to analyze the development trend of the WEE nexus. In addition, the Tobit regression model is employed to explain the WEE nexus' influencing factors. The result indicates that the WEE nexus is generally developing in Western China, and the interaction between WEE is also increasing, but there is a lag in the WEE nexus' coordinated development. Especially, the economic system had the largest increase, with the development level rising from 0.2166 to 0.4966. Further empirical study shows that water resources development, science and technology innovation, economic development, industrial structure, and ecological governance are the major factors affecting the WEE nexus' coordinated development. The forecast shows a steady upward trend of coupling coordination in Western China in 2023-2025, and the majority of provinces will exceed 0.7 in 2025, reaching the intermediate coordination. This study offers a decision reference for policymakers and practitioners in addition to enriching the knowledge body of water governance and sustainable development on both global and regional scales.