Population-land spatial coupling in urban non-core region and environmental pollution: evidence from urbanization in China

Urban non-core region land exploitation and population immigration toward urban non-core areas, two fundamentals of urbanization in China, challenge the environment; however, the pollution effect remains unclear. Using prefecture-level data in China between 2003 and 2020, our study investigates the pollution effect of population-land spatial coupling in the urban non-core region. The empirical results demonstrate that excessive urban non-core region land expansion alone negatively impacts the environment. Meanwhile, outward spatial population distribution in a town, primarily measured by the relative proportion of the urban non-core region population size, directly aggravates environmental pollution on the one hand and indirectly improves the environment by alleviating the adverse effect of land-led urbanization. These findings remain robust under various regional heterogeneity analyses and still stand regardless of the investigated pollutants. The practical implications suggest that breaking through the population-land spatial coupling when the urban core region is small is advisable; meanwhile, efforts in maintaining the coupling, especially for areas with sizeable peripheral land exploitation, should be held.