Spatial-temporal variation of ozone in Yangtze River Delta urban agglomeration in 2016
HUANG Xiao-gang1,2,3, ZHAO Jing-bo1,3
1. School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China;
2. School of Geographical Sciences, Shanxi Normal University, Linfen 041004, China;
3. National Demonstration Center for Experimental Geography Education, Shaanxi Normal University, Xian 710119, China
Based on the air quality monitoring data collected in 40 cities in Yangtze River Delta urban agglomeration in 2016, this study presents the spatial-temporal variation of O3 concentration in Yangtze River Delta urban agglomeration in 2016 via spatial interpolation, spatial autocorrelation analysis, and hotspot analysis. It shows that:1) with an average O3 non-attainment rate of 8.8percent, O3 has become the second major source of pollutants following PM2.5; 2) the O3 concentration is decreasing from summer, spring, autumn to winter, the monthly changing of O3 concentration follows a pattern of "M", with two peaks in May and August respectively, and a valley in June due to the interruption of the plum rain season; 3) the O3 non-attainment mainly occurs from April to September, which contributes 98.1% to the O3 non-attainment days during the whole year with an average monthly rate of 17.3%; 4) the O3 concentration shows an a general decrease trend from the northeast to southwest, and the line connecting Hangzhou and Ma'anshan highlights the difference between the highly polluted area in the eastern side of the line, and the less polluted area in the western side of the line. The cities around the Taihu Lake suffer from severest pollution. In geologically speaking, the spatial distribution of O3 is approximately in accord with that of the economic development levels of Yangtze River Delta urban agglomeration; 5) the O3 concentration follows the spatial agglomeration law. Owing to the impact of southeast monsoon, the hotspots of O3 are primarily distributed in the eastern part of the Lake Cities from April to July, and later, move westward to Nanjing and its adjacent areas from August to September.
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