摘要
为阻止新冠肺炎(COVID-19)疫情迅速蔓延,我国采取了严格的管控措施,在全国大部分城市PM2.5浓度显著下降的背景下,呼和浩特市PM2.5浓度不降反升,仍出现多次重污染过程,其成因尚不明确.基于环境空气质量自动监测数据(PM2.5、PM10、SO2、NO2、CO和O3),结合风速、风向、温度、相对湿度等气象数据,研究疫情期间大气污染特征及其影响因素,利用潜在源区贡献函数(PSCF)和浓度权重轨迹分析(CWT)识别污染物潜在源区,为呼和浩特市大气污染治理提供理论依据.研究结果表明:疫情期间呼和浩特市发生重度以上污染天6 d,占监测总天数的19.3％.与历史同期比较,疫情期间呼和浩特市PM2.5、PM10、CO和O3浓度均有不同程度上升,SO2和NO2呈降低趋势.与疫情前相比,疫情期间 PM2.5、PM10、SO2、NO2 和 CO 分别下降 38.6％、31.7％、46.1％、35.8％和 37.0％,O3上升109.4％.高相对湿度和低风速是呼和浩特市"疫情霾"形成的主要原因.疫情期间呼和浩特市大气PM2.5主要受本地源或近距离传输的影响.
Abstract
China has taken strict control measures to stop the rapid spread of COVID-19 epidemic.While PM2.5 concentration has significantly decreased in most cities in China,Hohhot suffered from many heavy pollution episodes during COVID-19 epidemic,the driven factor of that is still unclear.Based on the environmental air quality data(PM2.5,PM10,SO2,NO2,CO and O3)and meteorological data(wind speed,wind direction,temperature,and relative humidity),the characteristics and influencing factors of atmospheric pollution during COVID-19 epidemic were analyzed.The results showed that there were six severe pollution days,accounting for 19.3％of the total monitoring days in Hohhot during the epidemic period.Compared with the same period of 2019,the concentrations of PM2.5,PM10,CO and O3 in Hohhot significantly increased during the epidemic period,whereas the concentration of NO2 and SO2 significantly decreased.Compared with before epidemic period,the concentration of PM2.5,PM10,SO2,NO2 and CO decreased by 38.6％,31.7％,46.1％,35.8％and 37.0％,respectively,while O3 increased by 109.4％.The high relative humidity and the low wind speed were the main influencing factors of pollution episodes during the epidemic period.During the epidemic period,the concentration of PM2.5 in Hohhot was mainly affected by local sources or short-range transmission.
基金项目
国家自然科学基金(42167015)
内蒙古自治区科技计划项目(2022YFHH0126)
NETL
NSTL
万方数据