Abstract:In order to study the variation characteristics of air pollutants in Zunyi city of Yunnan Guizhou Plateau during the period of COVID-19 occurrence, the air quality monitoring data and surface meteorological observation of Zunyi from 2015 to 2020 were used to analyse the changes of Zunyi City main air pollutants and meteorological elements during the epidemic prevention and control period and study the response of air quality to pollutant emission reduction and meteorological factors.The results show that:epidemic prevention and control leads to the fact that the mass concentrations of PM2.5, PM10 and NO2 decreased significantly, but the mass concentration of O3 increased slightly;The response of PM2.5 and NO2 to human emission reduction was more sensitive. During the period of prevention and control, the meteorological conditions of Zunyi were conducive to the removal of pollutants. And the PM2.5 mass concentration decreased by 25.34% due to prevention and control measures. Under the background of epidemic prevention and control, O3 concentration was obviously higher and PM2.5 decreased significantly compared with 2015—2019,Which was related to the obvious reduction of people and vehicles going out during lockdown period, resulting in the reduction of gas consumption of O3 at night. Emission reduction measures have a significant weakening effect on the concentration of particulate matter pollution during the prevention and control period.
