Urban Spatial Structure and Water Ecological Footprint: Empirical Analysis of the Urban Agglomerations in China

Focusing on the water conservation of China's urban agglomerations (UAs), panel data covering 92 cities in the top five agglomerations from 2006 to 2020 are used to study the relationship between the spatial structure of UAs and the water ecological footprint (WEF) of their cities. WEFs and spatial structures are measured by the ecological footprint models and the rank-size law, respectively. Furthermore, the effects of spatial structure on WEF are estimated through the fixed-effects (FE) model with instrumental variables (IVs). Results suggest that the concentricity of the spatial structure has a nonlinear impact on the WEF, in that as the spatial structure moves away from polycentricity, the WEF first declines and then rises. By reducing the WEF through concentrated development, cities with a large proportion of production WEF or a large population can enjoy more benefits. Therefore, promoting the balanced development of JJJ and PRD and enhancing the role of the growth pole in CY and YRMR can help the water conservation of most cities. Moreover, considering household water use and small-population cities in other water-saving policies can serve as a policy reference in the future.