2016年长三角城市群O3浓度的时空变化规律

基于2016年长三角城市群40个城市的监测数据,利用空间内插、空间自相关分析、热点分析等地统计分析方法,研究了2016年长三角城市群O₃浓度的时空变化规律.结果表明：2016年长三角城市群O₃平均超标天数比例为8.8%,O₃已成为造成长三角城市群空气污染的仅次于PM_2.5的重要污染物;夏、春、秋、冬季O₃浓度依次递减,由于梅雨的影响,O₃月均浓度变化曲线呈M型分布,2个峰值出现在5月和8月,谷值出现在6月;O₃超标主要发生在4~9月,超标天数占全年的98.1%,月均超标天数比例为17.3%;O₃浓度具有明显的空间分异规律,大体呈东北高西南低的态势,过杭州和马鞍山的直线可将长三角城市群O₃浓度划分为高值区和低值区,杭州-马鞍山线以东是O₃高污染城市聚集区,尤以环太湖经济圈最为严重.O₃浓度的空间分布格局与长三角城市群经济发展格局大体一致;O₃浓度具有空间集聚规律,4~7月O₃热点集中分布在环太湖经济圈至上海区域,受东南季风加强的影响,8~9月热点西移至以南京为中心的区域.

Spatial-temporal variation of ozone in Yangtze River Delta urban agglomeration in 2016

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 PM_2.5; 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.