基于中国大气环境监测站点的2015—2019年大气质量状况时空变化分析

Analysis of the Temporal and Spatial Variation of Atmospheric Quality from 2015 to 2019 based on China Atmospheric Environment Monitoring Station

2013年以来几次严重的雾霾污染事件引起了公众的广泛关注,此后中国实施了一系列有关大气污染防治的政策、法规和措施来改善大气质量。为了分析近年来中国大气质量的时空变化特征,本文选取2015—2019年生态环境部国控站点监测的大气污染关键参数,对比分析了空气质量指数和6种大气污染物的季均、年均浓度变化结果,并利用组合指标分析法和相关分析法探讨了不同大气污染物之间的相关性。结果表明:①PM2.5、PM10、SO2、CO和NO2浓度和AQI均有明显下降,2019年均浓度较2015年均浓度分别下降4.5%、3.84%、7.86%、3.74%、0.95%,AQI下降了19.31%,同时,O3浓度则上升了0.79%;②从空间分布来看,中国北方地区PM10、PM2.5、O3、NO2、SO2、CO年均质量浓度和AQI分别比南方地区高25.2%、18.73%、4.95%、17.6%,32.74%、16.17%、28.3%;③从季节性变化规律来看,除了O3呈现出夏季浓度高,冬季浓度低外,其他5种污染物和AQI都呈现相反的季节变化规律;④总体而言,目前中国大气污染以PM2.5和O3为主,PM2.5与NO2、SO2、CO之间有极显著的正相关关系(r>0.85,p<0.01),而O3与其前体物NO2和CO之间存在显著的负相关关系(r>0.8,p<0.01)。

After 2013,several serious haze pollution events in China have attracted wide attention from the public.Therefore,the Chinese government has developed a series of policies,measures,and laws for air pollution prevention and control.We select the air quality index and six key air pollutant observations in the national air environmental monitoring station network of China to analyze the changes trend and spatial pattern of the country-scaled atmospheric quality from 2015 to 2019.The annual and seasonal average concentrations of these parameters were used to investigate their relationships by using the ratios and correlation coefficients among them.The results showed that the concentration of PM2.5,PM10,SO2,CO,NO2,and AQI all decreased significantly.The annual average concentrations of them in 2019 decreased by 4.5%,3.84%,7.86%,3.74%,0.95%,and 19.31%,respectively,compared with that in 2015.Only O3 significantly increased by 0.79%in the same period.The average annual concentrations of PM10,PM2.5,O3,NO2,SO2,CO,and AQI in northern China all are higher than those in southern China by 25.2%,18.73%,4.95%,17.6%,32.74%,16.17%,and 28.3%,respectively.Besides,AQI and all six pollutants showed the seasonality.The seasonal variation pattern of O3 exists with a higher concentration in summer and a lower concentration in winter,while the other five pollutants and AQI present the inverse seasonality.In general,PM2.5 and O3 are the most severe air pollutants in China during these five years.Furthermore,the relationships among different pollutants were found in the study period.The PM2.5 concentration is significantly positively correlated with NO2,SO2 and CO(r>0.85,p<0.01),and O3 is negatively correlated with its precursor NO2 and CO(r>0.8,p<0.01).