摘要
随着川南地区的经济发展,地面臭氧(O3)、细颗粒物(PM2.5)成为危害人体健康的主要污染物.本文分析了2015-2020年间川南地区(自贡、内江、泸州、宜宾)PM2.5和O3质量浓度的时间变化特征.以污染严重的自贡市为例,研究当地PM2.5和O3浓度与常见影响因素的相关性,并通过潜在源分析方法,探究污染物区域输送对自贡市的影响.结果表明:1)2015-2020年,川南地区年均PM2.5质量浓度呈下降趋势,年均O3质量浓度呈略上升趋势.月均PM2.5质量浓度呈"U"型分布,7-8月质量浓度低,12-2月质量浓度高;月均O3质量浓度呈"M"型分布,7、8月出现峰值,4、5月出现次峰值.2)自贡市PM2.5质量浓度与CO、NO2、SO2质量浓度呈显著正相关,O3质量浓度与气温、相对湿度分别呈显著正相关和负相关.3)自贡市PM2.5和O3的区域输送主要以局地气团为主,辐射和人为源排放强度影响气流轨迹中的PM2.5和O3质量浓度.PM2.5和O3的主要潜在源区位于四川盆地和贵州部分地区.
Abstract
With the economic development of southern Sichuan,ground-level ozone(O3)and particulate matter less than 2.5 μm in aerodynamic diameter(PM2.5)have emerged as major pollutants detrimental to human health.In response to air pollution challenges,the Chinese Government implemented the"Air Pollution Prevention and Control Action Plan"in 2013 and the"Three-Year Action Plan to Win the Blue Sky Defense War"in 2018.This study evaluates the effectiveness of control measures for PM2.5 and O3 in southern Sichuan post-implementa-tion and aims to provide a theoretical and scientific basis for the coordinated management of these pollutants.We analyze the temporal variations in PM2.5 and O3 concentrations in four cities in southern Sichuan(Zigong,Nei-jiang,Luzhou,and Yibin)from 2015 to 2020.Zigong,identified as the most polluted among the cities,serves as a case study to investigate the correlations between PM2.5 and O3 concentrations and various influencing factors.The study utilizes backward trajectory clustering,source emission intensity analysis,and potential source analysis to as-sess the impact of regional pollutant transport on Zigong.The results indicate that:1)From 2015 to 2020,the an-nual average concentration of PM2.5 in southern Sichuan showed a declining trend with a 38.9％reduction,while the annual average concentration of O3 showed a slight increasing trend,rising by 8.2％.These trends suggest that current control strategies are effective for PM2.5 but may be insufficient for O3,highlighting the need for enhanced O3 management strategies.2)The monthly average PM2.5 concentration exhibits a"U"shape,with the lowest val-ues in July and August and the highest from December to February.In contrast,the monthly average O3 concentra-tion exhibits an"M"shape,peaking in July and August with secondary peaks in April and May.These patterns suggest that PM2.5 control should be prioritized in winter,while O3 control should be emphasized in spring and summer.3)In Zigong,PM 2.5 concentration shows significant positive correlations with CO,NO2,and SO2 concen-trations,while O3 concentration is significantly positively correlated with temperature and negatively correlated with relative humidity.4)The regional transport of PM2.5 and O3 in Zigong is predominantly influenced by local air masses.Radiation levels and anthropogenic emission intensities along air trajectories significantly affect PM2.5 and O3 concentrations.The primary potential source areas for these pollutants are located within the Sichuan Basin and parts of Guizhou.Given the regional transport influnece,there is a need for strengthened regional collaborative governance,joint prevention and control efforts,enhanced source control,accelerated replacement of VOC-contai-ning materials,and increased utilization of clean energy soucres.The study employs Pearson correlation analysis to preliminarily identify relationships between PM2.5 and O3,and various influencing factors.Future research will in-clude a more quantitative analysis of these relationships,including the impact of temperature on photochemical re-actions,the role of relative humidity in PM2.5 wet deposition,and the effects of atmospheric diffusion conditions on pollutant concentrations.These analyses will provide precise quantification of the specific impacts of each influ-encing factor on PM2.5 and O3 pollution,thereby enhancing the objectivity and reliability of the research findings.
基金项目
国家自然科学基金项目(42205100)
四川省自然科学基金项目(2022NSFSC0982)
万方数据