2015~2021年京津冀及周边地区PM_(2.5)和臭氧复合污染时空特征分析

Spatiotemporal Distribution Characteristics of Co-pollution of PM_(2.5) and Ozone over BTH with Surrounding Area from 2015 to 2021

为了解京津冀及周边地区“2+26”城市PM_(2.5)和O_(3)复合污染时空分布特征,利用ArcGIS和SPSS软件对2015~2021年京津冀及周边地区“2+26”城市空气质量数据和气象数据进行关联性分析.结果表明:(1) 2015~2021年PM_(2.5)污染持续减缓,污染集中在区域中南部;O_(3)污染呈波动上升趋势,空间分布呈现“西南低,东北高”的格局.季节变化来看,PM_(2.5)浓度主要为:冬季>春季≈秋季>夏季,O_(3)-8h浓度为:夏季>春季>秋季>冬季.(2)“2+26”城市PM_(2.5)超标天数持续下降,O_(3)超标天数波动上升,复合污染日下降趋势显著;PM_(2.5)和O_(3)污染在夏季呈强正相关,相关系数最高达0.52,冬季呈强负相关.(3)对比典型城市臭氧污染时期与复合污染时期气象条件,复合污染发生的温度区间集中在23.7~26.5℃、湿度48%~65%和S~SE风向条件下.

PM_(2.5) and ozone co-pollution,which are harmful to not only human health but also the social economy,has become the pivotal issue in air pollution prevention and synergistic control,especially in Beijing-Tianjin-Hebei and its surrounding areas and"2+26"cities.It is necessary to analyze the correlation between PM_(2.5) and ozone concentration and explore the mechanism of PM_(2.5) and ozone co-pollution.In order to study the characteristics of PM_(2.5) and ozone co-pollution in Beijing-Tianjin-Hebei with its surrounding area,ArcGIS and SPSS software were used to analyze the correlation between air quality data and meteorological data of the"2+26"cities in Beijing-Tianjin-Hebei and its surrounding areas from 2015 to 2021.The results indicated:①PM_(2.5) pollution constantly decreased from 2015 to 2021,and the pollution was concentrated in the central and southern parts of the region;ozone pollution showed a trend of fluctuation and presented a pattern of"low in the southwest and high in the northeast"spatially.In terms of seasonal variation,PM_(2.5)concentration was mainly in the order of winter>spring≈autumn>summer,and O_(3)-8h concentration was in the order of summer>spring>autumn>winter.②In the research area,days with PM_(2.5) exceeding the standard continued to decline,whereas days with ozone exceeding the standard fluctuated,and days with co-pollution decreased significantly;there was a strong positive correlation between PM_(2.5) and ozone concentration in summer,with the highest correlation coefficient of 0.52,and a strong negative correlation in winter.③Comparing the meteorological conditions of typical cities during the ozone pollution period with that of the co-pollution period,the co-pollution occurred under the temperature range of 23.7-26.5℃,humidity of 48%-65%,and S-SE wind direction.