ANALYSIS OF OZONE POLLUTION SITUATION, CAUSES AND COUNTERMEASURES IN CHANGSHA IN 2019—2021

The impact of ozone on the quality of ecological environment is deepening. Based on the ozone data from 2019 to 2021, ozone levels are more likely to exceed the standard during the summer and autumn. During the key period of ozone pollution, the total radiation ≥0.85 MJ/m², the maximum temperature ≥32 ℃, and the relative humidity ≤65% are more effective meteorological conditions for ozone generation in Changsha. Based on the observation-based models (OBM), this work also presents the simulation of the optimal emission reduction scheme: the Changsha Environmental Protection Vocational College monitoring site area should separately reduce the proportion of VOCs by 40%; the Environmental Protection Bureau monitoring site area in the High-Tech Zone of Changsha should separately reduce the proportion of VOCs by 21%; the Mapoling monitoring site area can’t meet the standard, but separately reducing VOCs can lead to the fastest decrease in ozone concentration. Therefore, under adverse meteorological conditions, the O₃ concentration can be significantly reduced by designing scientific emission reduction programs.