新冠肺炎疫情期间冀南地区空气质量时空变化特征

为研究新冠肺炎疫情期间冀南地区空气质量变化规律,明确防疫管控措施对空气质量的具体影响及大气污染物排放特征,笔者综合分析了研究区域的常规监测数据和部分大气超级站的PM_2.5组分数据。结果表明:疫情防控重点区域石家庄市、邢台市空气质量整体好转,细颗粒物和一次排放气态污染物浓度下降明显,PM_2.5来源中燃煤、生物质燃烧源占比上升,机动车尾气源占比下降,体现出交通管制、企业限产和道路工地扬尘管理等环保措施的有效性。疫情防控高风险区域石家庄市藁城区出现了明显的NO₂浓度降低、PM_2.5污染好转现象,而O₃浓度显著升高成为新的特征污染物。结果显示,藁城区综合防疫管控举措对本地一次排放污染物起到了明显抑制作用。疫情防控核心区域藁城区增村镇因实行最严格的封村、限行、停产等措施,人为污染源排放"触底",6项监测指标中除O₃浓度同比、环比均大幅度升高外,其他污染物浓度全时段降低,SO₂和CO昼夜差距缩小,环境质量明显优于周边乡镇。分析认为大规模持续化学消杀可能对O₃浓度升高有影响,此问题需要进一步探讨。

Study on Spatial-Temporal Variations of Air Quality in Southern Hebei Province During the COVID-19 Epidemic

In order to study the change regularities of air quality in Southern Hebei during the epidemic period of COVID-19 in 2021,and to clarify the specific impact of control measures for epidemic prevention on air quality and the emission characteristics of air pollutants,the routine monitoring data of the study area and the PM_2.5 component data of some super stations were analyzed comprehensively.The results showed that:the air quality of Shijiazhuang and Xingtai,the key areas of epidemic prevention and control,improved as a whole,in which the concentration of fine particles and primary gaseous pollutants decreased significantly.The proportion of coal combustion and biomass burning in PM_2.5 sources increased,and the proportion of vehicular emission sources decreased,which proved the effectiveness of environmental protection measures such as traffic control,enterprise production restriction,and road site dust management.In Gaocheng District of Shijiazhuang City,a high-risk area for epidemic prevention and control,the concentration of NO₂ decreased significantly and the pollution of PM_2.5 improved,while the concentration of O₃ increased significantly and became a new characteristic pollutant.The results showed that the comprehensive epidemic prevention and control measures in Gaocheng District significantly inhibited the local primary emission of pollutants.Due to Zengcun Town,the core area of epidemic prevention and control,implemented the most strict measures such as closing,limiting traffic and stopping production,and so on,the artificial pollution source emissions hit the bottom.Among the six monitoring indicators,except for the concentrations of O₃ increased significantly,which increased significantly year-on-year and month-on-month,the concentration of other pollutants decreased during the whole period,the gap between day and night of SO₂ and CO narrowed and the ambient air quality was significantly better than that of the surrounding towns.Among the six monitoring indicators,the concentrations of other pollutants decreased during the whole period,except that the concentration of O₃ increased significantly year-on-year and month on month,the concentration of other pollutions is increased significantly.It was suggested that large-scale continuous chemical disinfection measures may affect the increase of O₃ concentration,which needed to be further studied.