新冠疫情对关中盆地空气质量的影响

Effects of Corona Virus Disease 2019 on air quality in Guanzhong Basin

基于新冠疫情紧迫形势,国家和地方政府果断采取了一系列防控方案,从侧面极大的减少了大气污染排放量(源),另一方面为解析人为活动对大气污染的影响提供了研究时机.本文结合气象、工业、交通等数据和资料,通过数学统计和空间分析等方法对关中盆地疫情期间和2019年同期空气质量及污染物浓度进行了详细的对比分析,并探讨了疫情前后空气质量变化的潜在原因.结果表明:疫情期间关中盆地空气质量的整体优良率为66%,空气质量整体得到改善;空气质量综合指数在疫情期间下降20%以上,但各市相差不大.与2019同期相比,除O_(3)外污染物浓度均出现不同程度下降,下降幅度呈现为:PM_(10)(25.6%)>PM_(2.5)(17%)>CO(16.4%)>NO_(2)(14.8%)>SO_(2)(13.6%),首要污染物分别为PM_(10)、PM_(2.5)、O_(3).伴随着PM_(2.5)和NO_(x)浓度的明显减小以及太阳辐射通量的显著增加,O_(3)的滴定作用减弱,使得O_(3)浓度有所增加(增幅约6%),并成为首要污染物.气象条件、工业与机动车是出现这种变化的重要因素.该研究结果有望服务于当地,为地方大气污染治理提供科学参考.

In view of the urgent situation of Corona Virus Disease 2019(COVID-19)over China,the national and local governments have taken a series of prevention and control programs decisively.On the other hand,which have greatly reduced the emissions(sources)of air pollution,and provided a research opportunity for analyzing the impact of human activities on air pollution.In presented study,combined with meteorological,industrial and traffic data,the air quality and pollutants concentrations in Guanzhong Basin during the epidemic period and the same period in 2019 were detailed analyzed by mathematical statistics and spatial analysis.Moreover,the potential causes of air quality changes before and after the epidemic were also discussed.The results showed that the overall excellent and good rate of air quality in Guanzhong Basin was 66%,while the air quality was improved as a whole period.The air quality composite index dropped by more than 20%during the outbreak of COVID-19,but there was little difference among cities.Compared with the same period in 2019,except the concentration of O_(3),the pollutants presented decreased trend with different degrees,while the decrease follows the order:PM_(10)(25.6%)>PM_(2.5)(17%)>CO(16.4%)>NO_(2)(14.8%)>SO_(2)(13.6%).The primary pollutant was PM_(10),PM_(2.5) and O_(3),respectively.With the significant decrease of PM_(2.5) and NO_(x) concentrations,as well as the significant increase of solar radiation flux,the titration effect of O_(3) is weakened,which further makes O_(3) concentration increase(about 6%)and becomes the primary pollutant.Meteorological conditions,industrial,and vehicle emissions are important factors and responsible for the air quality changes.The results of this study are expected to serve the government and provide scientific reference for air pollution prevention and control.