The Impact of Multi-Dimensional Urbanization on PM₂.₅ Concentrations in 261 Cities of China

Rapid urbanization has caused serious PM2.5 pollution. The existing researches mainly focus on the contribution of one aspect of urbanization to PM2.5 concentrations. However, few studies have comprehensively considered the direct and indirect effects of multi-dimensional urbanization on PM2.5 concentrations. In order to identify the impact of multi-dimensional urbanization on PM2.5 concentrations, the entropy-right method, the spatial lag model, spatial error model and spatial Durbin model were used to investigate the relationships between multi-dimensional urbanization and PM2.5 concentrations in 261 cities of China in 2016. Results demonstrated that the spillover effect of PM2.5 concentrations between different cities was significant. Economic urbanization had the strongest direct effect on PM2.5 concentrations. Social urbanization and ecological urbanization had a significantly negative impact on PM2.5 concentrations in local cities. However, the biggest indirect effect on PM2.5 concentrations in adjacent cities was social urbanization, followed by land urbanization. The direct and indirect effects of population urbanization on PM2.5 concentrations were non-significant and the least. The findings from this result analysis and discussion can be used as a theoretical basis to provide some policy suggestions for China's air governance and sustainable urban development.