武汉市大气污染物时空分布与区域传输贡献

Spatiotemporal Pattern and Regional Transport Contribution of Air Pollutants in Wuhan City

随着近年来武汉市社会经济的高速发展,严重的空气污染事件也日益频发,受到了当地政府和大众的广泛关注。该研究利用2017年PM2.5、PM10、SO2、CO、NO2和O3实时监测数据,通过时间序列模型、空间统计方法、潜在源贡献因子分析模型和浓度权重轨迹分析模型研究了不同季节武汉市主要大气污染物的时空变化规律和污染物潜在来源。结果表明,武汉市环境空气质量当前还是以颗粒物污染较突出;主要污染物的小时质量浓度均呈现双峰型分布,且峰值出现在交通早晚高峰的时间段之后,O3呈单峰型分布,峰值出现在15∶00-16∶00;在大气污染物空间分布上,中心城区除O3浓度均值较低外,其余污染物浓度都较高,远城区则呈相反的变化规律;通过后向轨迹分析、污染物贡献因子分析和轨迹权重浓度分析表明,不同季节武汉市大气污染物潜在源区分布有一定差异,春季湖北省南部及江西省西北部等区域对PM2.5、PM10有较大贡献,而湖北省东南部、江西省西北部区域对NO2有较大贡献,夏季武汉市外部区域对大气污染物贡献较小,秋季荆门、襄阳区域对PM2.5、PM10的传输有较大贡献,冬季湖北省东部地区是武汉市PM2.5、PM10污染的主演潜在源区。

With the rapid development of society and economy in recent years,severe air pollution incidents had become more frequent in Wuhan,and they had become a hot topic from the local government and the public.Based on the realtime monitoring data of PM2.5,PM10,SO2,CO,NO2 and O3 in 2017,the temporal and spatial variation of major air pollutants and their potential sources in Wuhan in different seasons are investigated by time series model,spatial statistical method,PSCF model and CWT model.The results show that particulate matter pollution is still the most prominent environmental air quality in Wuhan.The hourly mass concentrations of major pollutants all present a bimodal distribution,and the peak value appears after the morning and evening rush hour of traffic,while O3 presents a unimodal distribution,with the peak value appearing from 15∶00 to 16∶00.In terms of the spatial distribution of atmospheric pollutants,the concentration of other pollutants in the central urban area is relatively high except for the low average O3 concentration,while the concentration in the far urban area shows the opposite change rule.Through backward trajectory analysis,pollutant contribution factor analysis and trajectory weight concentration analysis,it is shown that the distribution of potential source regions of atmospheric pollutants in Wuhan is different in different seasons.In spring,regions such as southern Hubei Province and northwest Jiangxi Province have greater contribution to PM2.5 and PM10,while regions such as southeast Hubei Province and northwest Jiangxi Province have greater contribution to NO2.In summer,the outside regions of Wuhan contribute less to atmospheric pollutants,while Jingmen and Xiangyang regions have greater contribution to the transmission of PM2.5 and PM10 in autumn.In winter,eastern Hubei Province is the main potential source region of PM2.5 and PM10 pollution in Wuhan City.