Analysis of the Characteristics of Ambient Air Quality of the Largest City in Southern Xinjiang from 2018 to 2022
The characteristics of ambient air quality and the pollutant concentration level of Korla city,the largest city in southern Xinjiang is analyzed by the monitoring data of PM2.5,PM10,SO2,NO2,CO and O3 concentration from 2018 to 2022.The results showed that the air quality of Korla city has been improving from 2018 to 2022.The number of days with excellent air quality has increased from 223 days in 2018 to 250 days in 2022,and an increase of 27 days.The air quality compliance rate has increased from 62.5％in 2018 to 68.5％in 2022,and an increase of 6.0％.The number of days with severe or above pollution has decreased by 23.3％.The air quality index(AQI)has decreased by 5.4％,but the AQI values for five years are all above 100,indicating that average annual air quality in Korla city is at a mild pollution level.The concentrations of SO2 and CO show a decreasing trend year by year,and the NO2 concentration does not change significantly,but the average annual and seasonal values of SO2,NO2 and CO are superior to the first level standard of national ambient air pollutant concentration limit.The annual average value of O3 is lower than the first level standard of national ambient air pollutant concentration limit,but the interannual variation of O3 in all four seasons shows an upward trend,and the O3 concentrations in the summer and autumn of 2021 and 2022 are all higher than 100 µg·m-3.From 2018 to 2022,the concentration of PM2.5 in Korla city shows a downward trend,PM10 does not change significantly.However,the annual concentration of PM1o is twice higher than the second level standard of national ambient air pollutant concentration limit(70 µg·m-3),indicating that the PM10 pollution in Korla city is very serious in recent years.In addition,the PM2.5/PM10 ratio is highest in January and lowest in March every year,indicating that the concentration of particulate matter with a diameter greater than 2.5 μm gradually increases from January to March.This is mainly because Korla city is affected by sandstorms every spring.
NETL
NSTL
万方数据
