Spatial Autocorrelation and Temporal Convergence of PM_2.5 Concentrations in Chinese Cities

Scientific study of the temporal and spatial distribution characteristics of haze is important for the governance of haze pollution and the formulation of environmental policies. This study used panel data of the concentrations of particulate matter sized < 2.5 μm (PM_2.5) in 340 major cities from 1999 to 2016 to calculate the spatial distribution correlation by the spatial analysis method and test the temporal convergence of the urban PM_2.5 concentration distribution using an econometric model. It found that the spatial autocorrelation of PM_2.5 seemed positive, and this trend increased over time. The yearly concentrations of PM_2.5 were converged, and the temporal convergence fluctuated under the influence of specific historical events and economic backgrounds. The spatial agglomeration effect of PM_2.5 concentrations in adjacent areas weakened the temporal convergence of PM_2.5 concentrations. This paper introduced policy implications for haze prevention and control.