[Regionalization and Analysis of PM2.5 and O3 Synergetic Prevention and Control Areas Based on Remote Sensing Data].

Site-based air pollution monitoring data cannot support the regionalization of air pollution prevention and control areas. Faced with this problem, this study proposed a method of regionalizing synergetic prevention and control areas based on multi-source remote sensing data and GIS spatial statistical analysis methods and carried out quantitative analyses of PM2.5 and O3 air pollution in China from 2015 to 2020. The results showed that there was an obvious decrease in PM2.5 concentrations, and O3concentrations remained stable; PM2.5 pollution mostly occurred in autumn and winter, and O3 pollution occurred in spring and summer. A significant spatial inconsistency was shown between the change rate of PM2.5 and O3 concentrations, in which the proportions of PM2.5 decreasing and O3 increasing, PM2.5 and O3 both decreasing, PM2.5 and O3 both increasing, and PM2.5 increasing and O3 decreasing accounted for 38.34%, 35.12%, 15.24%, and 10.89%, respectively. The results also showed that the boundary of PM2.5 and O3 synergetic prevention and control areas was dynamic during 2015 and 2020, showing a trend of expanding from 2015 to 2018 and then becoming smaller after 2019. Generally, the scope of PM2.5 and O3 synergetic prevention and control areas was concentrated in "2+26" cities, Fenwei plain, north of the Yangtze River Delta, and Shandong. In contrast, the regional scopes of "PM2.5 first" and "O3 first" were relatively stable. Areas of "PM2.5 first" were mainly carried out in Liaoning-Jilin, Hubei-Hunan-Jiangxi, Chengdu-Chongqing, and Taklimakan-Hexi Corridor, whereas "O3 first" areas were mainly in specific regions of the Pearl River Delta, Yangtze River Delta, and surrounding areas of Bohai Bay. Remote sensing-based PM2.5 and O3 mapping has the advantages of full-coverage and fine spatial simulation, which can support the regionalization of synergetic prevention and control areas and implementation of policies.