成渝地区中小型城市臭氧污染特征分析——以内江市为例

根据2015—2022年内江市国控空气质量监测数据,对内江市臭氧(O3)污染特征进行分析,结果表明:内江市O3污染呈现“春夏高、秋冬低”和双峰型变化的特点;臭氧滑动8小时(O3-8 h)浓度最高值分布在7—8月,春季和秋季污染有加重趋势。各年度O3小时浓度变化基本一致,小时峰值主要出现在16:00。斯皮尔曼(Spearman)秩相关系数显示,O3首次为首要污染物日期、O3污染负荷、O3超标天数和O3为首要污染物比例均呈现显著性不利变化;O3-8 h第90百分位浓度有上升趋势,2022年O3首次取代细颗粒物成为内江市主要污染物,成为制约内江市空气质量的关键因子。

According to the air quality monitoring data of Neijiang State Control stations from 2015 to 2022,the characteristics of ozone pollution in Neijiang City were analyzed.The results show that O3 pollution in Neijiang City presents a bimodal pattern of“high in spring and summer,low in autumn and winter”.The highest concentration of O3-8h is distributed in July and August,and the pollution tends to worsen in spring and autumn.The change of O3 hourly concentration is basically the same in each year,and the hourly peak value mainly appears at 16:00.Spearman rank correlation coefficient shows that the date when O3 is the primary pollutant for the first time,the O3 pollution load,the number of days that O3 exceeds the standard,and the proportion of O3 is the primary pollutant all have significant adverse changes.The 90th percentile concentration of O3-8h has a rising trend.In 2022,O3 replaced fine particulate matter as the main pollutant in Neijiang City for the first time,and became the key factor restricting air quality in Neijiang City.