[Spatio-temporal Variation of PM_2.5 Related Relationships in China from the Perspective of Air Pollution Regional...

Identification of spatio-temporal variation of PM_2.5 related relationships under joint management zones is of great significance for scientifically conducting joint control of air pollution in China. Based on the PM_2.5 concentration data of 334 prefecture-level cities in China from 2000 to 2016, from the perspective of air pollution regional linkage control and prevention, this paper systematically analyzes the spatio-temporal variation of PM_2.5 related relationships in China using a spatial unit aggregation strategy and geographically and temporally weighted regression. The results show that:① With PM_2.5 as the primary pollutant, ten air pollution joint management areas are obtained by considering the degree of pollution, geographical location, meteorology, topography, and economy. ② Geographically and temporally weighted regression can effectively reveal the spatio-temporal non-stationarity of the relationships between PM_2.5 concentration and related factors. Meanwhile, population size, secondary industry gross domestic product, SO₂ emissions, annual average temperature, annual precipitation, and annual relative humidity are identified as having a significant effect on changes in PM_2.5 concentration. ③ The population impacts on PM_2.5 concentration in the Beijing-Tianjin-Yunmeng region are the largest of all regions during the period. The influence of the secondary industry's gross domestic product on the PM_2.5 concentration in the Sichuan-Yunnan District is the most variable. Apart from these values in the northeast of China, the regression coefficient values of SO₂ emissions first decrease with time, then increase, and then decrease again. The time variability of the average annual temperature of each treatment area to PM_2.5 is small. The influences of annual precipitation and annual average relative humidity on PM_2.5 present different variability characteristics in each region.