北京市2014年APEC期间及前后城区大气污染物变化特征

Variation Characteristics of Air Pollutants in Urban Area of Beijing before, during and after 2014 Meeting of APEC

该文选择北京城区12个空气质量监测点,研究APEC前后及期间污染物时空变化特征及相互关系,并从不同角度分析污染物时空变化的影响因素,探讨APEC期间采取的临时减排措施对污染物的影响。结果表明:除O_3外,APEC期间污染物浓度低于非APEC期间,各污染物浓度在会间逐日变化呈"M"型、日变化最为平稳(α=0.05,Sig>0.05),基本呈从北至南、从西至东的递增趋势,O_3浓度空间变化和NO_2的相反耦合度最高(p=0.01,r<-0.80);PM_(2.5)、SO_2、NO_2和CO相互间在不同时段呈不同水平的正相关关系,但O_3在和其他污染物呈负相关。大气污染物浓度主要受排放源、气象因素、区域传输及污染物相关性等综合因素的影响,通过回归分析发现SO_2、NO_2、CO浓度和温度负相关性显著(α=0.05,Sig<0.05),NO_2、CO、PM_(2.5)和湿度负相关性极显著(α=0.05,Sig=0.00<0.05)。PM_(2.5)为APEC期间首要污染物,PM_(2.5)浓度在各因素综合影响下降低,使得会间空气质量达到优良水平,因此,APEC期间采取的减排措施取得成效,可为相关环保部门采取合理有效的环保手段提供指导。

In purpose of probing into the spatial-temporal distribution, interrelationships of air pollutants before, after and during the meeting of APEC, which was held in Beijing in the middle of November, 2014, air quality monitoring stations in Beijing, a total of twelve among others, were selected to investigate the effects of temporary mitigation measures carried out during the pe- riod of APEC on the air quality. The investigation showed that concentrations of the air pollutants except 03 during the APEC were lower than those before and after the period of APEC, the diurnal variation of pollutants concentrations was the mildest （a= 0.05,Sig〉0.05）, and the daily variation tended to ＂M＂ type, pollutants concentrations gradually increasing from north to south and from west to east, furthermore, the reverse coupling degree of spatial variation of 03 against NO2 was the highest （p=0.01, r〈- 0.80）. In addition, concentrations of PM25, SO2, NO2and CO were positively correlated with one another in different levels during the different periods but for 03 that was negatively correlated with others. The investigation also suggested that the concentration of air pollutants was mainly influenced by the pollution sources, regional pollutants transport, meteorological factors and the cot- relationship of the pollutants, etc. and by regression analysis it was found that temperature was negatively corrected with concen- trations of SO2, NO2 and CO notably（ a=0.05, Sig〈0.05 ） while concentrations of NO2, CO, and PM2.5 were very much positively correlated with air humidity （a=0.05,Sig=0.00〈0.05）. Furthermore, it was found that PM2.5 was a primary pollutant, but its concentration dropped off due to the combined effects of a variety of factors, which made the air quality attain fairly good during the APEC period. In conclusion, measures of energy conservation and emissions reduction taken during the meeting of APEC resulted in good environmental benefits, and the experience could be an example for the environmental administration departments to take a reasonable and effective measure.