2015~2022年北海市环境空气质量变化趋势及污染特征分析

Analysis on Trends and Pollution Characteristics of Ambient Air Quality in Beihai City from 2015 to 2022

利用2015~2022年北海市环境空气国控自动监测站数据,分析北海市环境空气质量及六项污染物浓度变化趋势,并研究其大气污染特征。结果表明:北海市环境空气质量总体改善显著,但由于O_(3)超标情况未得到有效控制,导致环境空气质量整体改善的幅度与优良天数比例的提升并不匹配。北海市大气污染主要分为以PM_(2.5)污染为主导的阶段、PM_(2.5)和O_(3)为特征的复合污染阶段和以O_(3)污染为主导的阶段。自2019年起,O_(3)已成为影响北海市环境空气质量的主导因素,防控O_(3)轻微超标被证实对提升优良天数比例成效显著。北海市O_(3)污染时段主要集中在9~11月,而PM_(2.5)污染时段主要集中在1~2月和12月。秋冬季污染精准防控是持续改善北海市环境空气质量的关键手段。

Based on the data of the state-controlled environmental air quality automatic monitoring station in Beihai from 2015 to 2022,the variation trend of ambient air quality and concentrations of six air pollutants were analyzed,and its air pollution characteristics were studied.The results showed that the ambient air quality in Beihai had improved significantly.However,the rising of O_(3) pollution had not been controlled effectively,which leaded to the mismatch between the improvement of overall ambient air quality and the increase of the ratio of days with good air quality in Beihai.The air pollution in Beihai were mainly divided into three stages included the stage dominated by PM_(2.5) pollution,the compound pollution characterized by PM_(2.5) and O_(3),and the stage dominated by O_(3).O_(3) has become the dominant factor affecting the ambient air quality in Beihai since 2019.Controlled of slightly exceeding the standard has been proved to be effective in increasing the ratio of days with good air quality in Beihai.The pollution period of O_(3) was mainly observed between September to November,while the outbreak time of PM_(2.5) pollution were founded in January,February and December.Precision prevention and control pollution will be the key to continuously improving ambient air quality in Beihai in autumn and winter.