Change trend of air quality in Hohhot from 2019 to 2022
Objective To understand the change trend of ambient air quality in Hohhot from 2019 to 2022 andto discussthe variation rule of pollutant concentration at different time scales(year,month,season and week).Methods The data of air quality index and PM2.5,PM10,CO,NO2,O3 and SO2 concentrations in Hohhot from January 2019 to December 2022 were collected,and the changing trends at different time scales were analyzed.Results From the perspective of the annual change of pollutant concentration,the proportion of days with excellent and good air quality in Hohhot increased from 2019 to 2022,and the air quality improved significantly.After 2020,the AQI index decreased significantly.From the monthly variation of pollutant concentration,the monthly average concentration of each pollutant was high in the cold season(10-April of the next year)and low in the warm season(May-September).From the analysis of seasonal variation characteristics,PM2.5 and PM10 had higher concentrations in the four seasons.The difference was that the concentration of PM2.5 and PM10 in summer was low,while the concentration in spring,autumn and winter was high.The weekly changes of the concentrations of the six pollutants were similar.On Monday and Tuesday,they were flat or decreased,slightly increased on Wednesday,peaked near Thursday,and then gradually decreased on Friday and Saturday.Conclusion We should focus on the seasons and months with serious air pollution,strengthen pollution control,and further promote the improvement of air quality in Hohhot.
NETL
NSTL
万方数据
