Unveiling disparate urban-rural relations in China through catchment area mapping

Sustainable urbanization in the Global South demands a comprehensive understanding of the intricate urban-rural relations in the face of rapid transformation. Traditional dichotomous urban-rural classification fails to thoroughly capture the convoluted interactions within the increasingly complex urbanizing landscape. Here, we reconstruct the urban-rural relationship in China by employing high-resolution satellite land-cover data in an urban-rural catchment area (URCA) framework to redefine urban-rural boundaries and quantify fine-grained connectivity. We categorize land areas into urban centers, peri-urban regions, rural areas, and hinterlands, revealing their respective population distributions in 2018. Our findings show significant spatial disparities in China's urban-rural relations due to transitioning from a predominantly rural to an urbanizing nation. The study also highlights substantial supply-demand inconsistencies in public infrastructure and fiscal preferences, exacerbating social expenditure gaps among municipal levels within the URCA. Our research contributes to understanding geographic social integration in urban-rural relations, which is important to promoting social justice and mitigating inequalities associated with China's urbanization in the context of the Sustainable Development Goals (SDGs).