2018年春节期间京津冀及周边地区烟花禁放效果评估

为了评估2018年春节期间（2月15—16日）京津冀及周边地区“2+26”城市烟花禁限放措施的效果，采用浓度特征对比、ρ（PM_2.5）/ρ（CO）等方法，对“2+26”城市的ρ（PM_2.5）、ρ（PM₁₀）、ρ（SO₂）、ρ（NO₂）进行分析，并定量估算了除夕夜烟花燃放对ρ（PM_2.5）和ρ（SO₂）的贡献率.结果表明:“2+26”城市烟花的集中燃放会导致ρ（PM_2.5）、ρ（SO₂）显著增长，出现以PM_2.5为首要污染物的重污染时段，2018年12月16日03:00区域内14个城市ρ（PM_2.5）达到重度及以上污染水平，呈区域性污染特征；与2017年同期（1月27—28日）相比，2018年春节期间（2月15—16日）14个城市烟花燃放对ρ（PM_2.5）平均贡献量呈下降趋势，其中，淄博市、济南市、北京市降幅最大，分别下降了85.2%、74.6%和65.2%，表明烟花禁限放措施起到了显著的污染削峰作用；与城区相比，周边郊县ρ（PM_2.5）显著高于城区，呈“农村包围城市”的现象，说明城区监测点位受到郊县等周边地区烟花燃放的传输影响.研究显示，虽然城区烟花禁限放措施起到了显著的削峰作用，但城区监测点位空气质量仍受到郊县等周边地区烟花燃放的传输影响，导致大气重污染的发生. 

Evaluation of the Effect of Fireworks Prohibition in the Beijing-Tianjin-Hebei and Surrounding Areas during the Spring Festival of 2018

In order to evaluate the effect of fireworks prohibition and restrictions for the air pollution control in the '2+26' cities during the Spring Festival in 2018 (February 15th to 16th), online data of ρ(PM_2.5), ρ(PM₁₀), ρ(SO₂), ρ(NO₂) were analyzed by comparing concentration characteristics and the ratio of ρ(PM_2.5) to ρ(CO). Moreover, the contribution of fireworks emission to ρ(PM_2.5) and ρ(SO₂) on New Year's Eve were also discussed. The results revealed that the fireworks emission significantly increased ρ(PM_2.5) and ρ(SO₂) in the '2+26' cities. The severe pollution episodes caused by PM_2.5 occurred in many cities. Particularly, 14 cities' air pollution reached significantly high levels or above at 03:00 AM on February 16, 2018, which presented the typical regional pollution characteristics. The characteristics also presented at the regional level. Also, compared to the average contribution of the fireworks during the 2017 Spring Festival (January 27th to 28th), there was a decrease in the fireworks emissions in the 14 cities in 2018 Spring Festival (February 15th to 16th). Meanwhile, the contribution from fireworks emissions in Zibo City, Jinan City and Beijing declined by 85.2%, 74.6% and 65.2% respectively, which indicated the great reduction effects of the fireworks prohibition and restrictions. The concentration of ρ(PM_2.5) in countryside and urban areas were also explored in this study. The results showed that the ρ(PM_2.5) in the countryside was significantly higher than that in urban areas, which implied the monitoring sites in the cities were impacted by the fireworks in the surrounding counties and areas. The research showed that there was an effective reduction in ρ(PM_2.5) due to the fireworks prohibition and restrictions in the rural and urban areas. But yet, severe air pollution was still occurred in the some urban areas because of the impact of the fireworks in the surrounding areas.