2020年1—3月四川地区大气污染物变化特征分析

Variation characteristics of air pollutants in Sichuan region during January-March of 2020

利用2018—2020年中国环境监测总站全国城市空气质量实时发布平台公布的监测点数据以及中国气象局气象站点的同期地面观测资料,采用相关性分析的方法对2020年1—3月四川地区大气污染物的变化特征进行分析。结果表明:由于2020年1—3月人为排放源管控政策的实施,成都、绵阳、宜宾和攀枝花的NO_(2)和PM_(10)浓度相比2018—2019年同期平均下降幅度达到30%,而O_(3)质量浓度在四座城市的日均值却分别上升了15.21%、10.32%、5.03%和0.42%。同时,O_(3)与相对湿度成负相关关系,与温度、风速和降水成正相关关系且相关系数都超过了0.7。O_(3)的反常增长不仅是受到气象要素的影响,较低的氮氧化物和PM_(10)浓度也间接维持了O_(3)的存在。严格的污染物排放控制措施对主要污染物排放影响较大,但对臭氧等次生污染物的影响较小,次生污染物污染的防治依旧面临严峻挑战。

Based on the monitoring data published by the China Environmental Monitoring Station and ground observation data of the China Meteorological Administration during 2018-2020,the variation characteristics of air pollutants in Sichuan province from January to March of 2020 were analyzed using the correlation analysis method.The results show that due to the implementation of anthropogenic emission source control policies from January to March of 2020,the concentrations of NO_(2) and PM_(10) in Chengdu,Mianyang,Yibin,and Panzhihua decrease by 30%on average compared with the same period of 2018-2019.However,the daily mean of O_(3) mass concentration in the four cities increases by 15.21%,10.32%,5.03%,and 0.42%,respectively.At the same time,the correlation analysis of O_(3) with relative humidity,temperature,wind speed,and precipitation shows that O_(3) is negatively correlated with relative humidity,and positively correlated with temperature,wind speed,and precipitation,with the correlation coefficients exceeding 0.7.The abnormal growth of O_(3) is not only affected by meteorological elements but also indirectly maintained by low nitrogen oxide and PM_(10) concentrations.Strict pollutant emission control measures have a great impact on the emission of major pollutants,but less impact on secondary pollutants such as ozone.The prevention and control of secondary pollutant pollution are still facing severe challenges.