太原市城区大气PM_(2.5)和PM_(10)时空分布特征

Characteristics of Temporal and Spatial Distribution of Atmospheric PM_(2.5) and PM_(10) in Urban Taiyuan,China

研究太原市城区大气颗粒物质量浓度时空变化规律,可以为实施更有效的大气污染综合治理手段提供科学依据。以太原市9个国家空气质量自动监测站的数据为基础,运用统计分析和Kriging插值法,对太原市城区2019年大气颗粒物的时空分布进行了分析。结果表明,2019年太原市城区PM_(2.5)和PM_(10)年均质量浓度分别为56μg·m^(−3)和107μg·m^(−3),是国家二级标准限值的1.60、1.53倍,以PM_(2.5)和PM_(10)为首要污染物占总超标天数的44.03%和12.58%;PM_(2.5)/PM_(10)年均值为0.52,PM_(2.5)对PM_(10)贡献较大;PM_(2.5)季平均质量浓度为冬季(87μg·m^(−3))>秋季(50μg·m^(−3))>春季(49μg·m^(−3))>夏季(34μg·m^(−3)),PM_(10)为冬季(123μg·m^(−3))>春季(120μg·m^(−3))>秋季(98μg·m^(−3))>夏季(64μg·m^(−3));PM_(2.5)和PM_(10)质量浓度月变化呈U型,二者平均质量浓度1月最高,8月最低;PM_(2.5)和PM_(10)24 h质量浓度变化呈“单峰单谷”型,峰值在10:00,谷值在17:00;取暖期PM_(2.5)与CO、SO_(2)和NO_(2)相关性高于其他时段;太原市城区PM_(2.5)和PM_(10)质量浓度空间分布总体上呈北低南高之势,PM_(2.5)春夏秋季的空间分布格局与太原市城区生产、生活、交通干道分布格局比较吻合。以上结果提示秋冬季是太原市城区颗粒物治理的关键时期,位于南部的小店和晋源区为重点防控治理区域。

This study stressed on the temporal and spatial changes of atmospheric particulate matter concentration in Taiyuan City,aiming to understand the current situation of local air pollution and provide an effective and scientific basis on the control measures.Based on the data from 9 state air quality monitoring stations in Taiyuan City,the temporal and spatial distribution of atmospheric particulate matter in 2019 was analyzed by using statistical analysis and the Kriging interpolation method.The results showed that the annual average mass concentrations of PM_(2.5) and PM_(10) in urban Taiyuan in 2019 were 56μg·m^(−3) and 107μg·m^(−3),respectively,which are 1.60 and 1.53 times higher than the state secondary standard limits.Furthermore,the days in which PM_(2.5) and PM_(10) acted as the primary pollutants accounted for 44.03%and 12.58%,respectively,in the total number of days exceeding the standard.The annual average value of PM_(2.5)/PM_(10) was 0.52,suggesting that PM_(2.5)contribute more to PM_(10)than PM_(2.5)‒10.The seasonal average mass concentration of PM_(2.5)in descend order was winter(87μg·m^(−3))>autumn(50μg·m^(−3))>spring(49μg·m^(−3))>summer(34μg·m^(−3)),while that of PM_(10)was winter(123μg·m^(−3))>spring(120μg·m^(−3))>autumn(98μg·m^(−3))>summer(64μg·m^(−3));the monthly variation of PM_(2.5)and PM_(10) mass concentration showed a U-shape,with the highest in January and the lowest in August.For the hourly variation of PM_(2.5) and PM_(10) mass concentration in a day,it appeared a“single peak and single valley”pattern,with the peak value at 10:00 and the valley value at 17:00.In the heating period,the correlation relationship between PM_(2.5) and other pollutants such as CO,SO_(2) and NO_(2) was better than that in other periods.In general,in terms of spatial distribution,the mass concentrations of PM_(2.5) and PM_(10) were higher in the south and lower in the north of Taiyuan.In spring,summer and autumn,the spatial distribution pattern of PM_(2.5) was consistent with their emission sources of industrial production,living,traffic distribution.The study highlighted that the seasons of autumn and winter were the key periods for the prevention and control of atmospheric particulate matter pollution in urban Taiyuan,especially in Xiaodian and Jinyuan District,which are situated in the south of the city.