Temporal and Spatial Changes of PM 2.5 Pollution in China from 2013 to 2015
Since the first nationwide ground level monitoring of PM2.5 in China in 2013, there have been few studies analyzing the overall spatiotemporal changes of PM2.5 pollution in the past three years at the national spatial scale, identifying the spatial range of PM2.5 pollution exacerbation or mitigation, and lacking direct comparative evaluation of the differences in PM2.5 pollution characteristics changes inside and outside the national key air pollution prevention and control areas. Based on PM2.5 monitoring data from 2013 to 2015, Comprehensively utilizing spatiotemporal statistical analysis and spatial interpolation mapping methods, revealing the past 3 years ρ (PM2.5) and the spatiotemporal variation pattern of pollution days at different levels, with a focus on comparing and analyzing the inside and outside of the "three zones and ten groups" region ρ The difference in changes in (PM2.5). The results show that from 2013 to 2015, there were 335 monitoring stations out of 413 continuously monitored nationwide ρ The average annual concentration of (PM2.5) has decreased, with 218 stations achieving two consecutive years of annual concentration reduction and 74 stations ρ The average annual value of (PM2.5) has been reduced to meet the national second level standard; Most parts of the country ρ The annual exceeding standard rate of (PM2.5) has decreased from over 50% to below 30%, the proportion of heavily polluted sites has decreased from 88.38% to 73.77%, and the proportion of severely polluted sites has decreased from 65.86% to 36.35%; The PM2.5 pollution in the Yangtze River Delta urban agglomeration, Changzhutan urban agglomeration, Wuhan and surrounding urban agglomeration, and Shaanxi Guanzhong urban agglomeration shows a significant improvement trend; Xizang, the Yunnan-Guizhou Plateau, urban agglomeration on the west side of the Straits, Pearl River Delta urban agglomeration and other coastal areas ρ (PM2.5) has been consistently low, with relatively good air quality; However, at the same time, the Beijing Tianjin Hebei urban agglomeration, the Shandong Peninsula urban agglomeration, and the central and northern regions of Henan Province are still areas of heavy PM2.5 pollution in China. New PM2.5 heavy pollution patterns are gradually forming in southwestern Xinjiang, Hefei, Nanchang, and other regions