“2+26”城市大气重污染下PM2.5来源解析

基于区域大气环境模拟系统RegAEMS开发了大气污染物来源解析模块APSA，以京津冀及周边"2+26"城市为研究对象，模拟2017年12月26日~2018年1月2日该地区一次PM_2.5重污染过程，对PM_2.5进行区域和行业来源解析.结果表明：本次污染持续时间长、影响范围广、污染程度重，"2+26"城市PM_2.5小时最大值为201~507μg/m³，RegAEMS可较好模拟出PM_2.5时空分布；区域来源解析表现为外围区域对"2+26"边界城市影响较大，贡献为15.3%~57.5%，"2+26"中部城市受外围区域影响较小，贡献为0.3%~8.4%，区域传输特征明显，受近地面风场影响较大；行业来源表现为区域内生活源、工业源贡献较大，分别为26.6%~45.8%、16.4%~37.8%，交通源占比13.0%~35.9%.本文研究表明RegAEMS可以实现重污染过程PM_2.5的数值模拟和来源解析，在大气污染精准管控方面具有较好应用前景.

Source apportionment of PM2.5 under heavy air pollution conditions in “2+26” cities

The Regional Atmospheric Environment Modeling System (RegAEMS) was used to simulate a severe PM_2.5 pollution event from December 26, 2017 to January 2, 2018 at "2+26 cities" in the Beijing-Tianjin-Hebei region and its surrounding areas. Based on RegAEMS, a module named Air Pollution Source Apportionment (APSA) for pollutant source apportionment was developed to analyse the regional and industrial sources of PM_2.5 in "2+26" cities. This pollution event was characterized by long duration, broad influence and serious pollution, with the hourly maximum PM_2.5 concentration reaching 201~507μg/m³. The results showed that RegAEMS could well simulate the temporal and spatial distributions of PM_2.5 during this period of heavy pollution. The regional source contribution showed that the peripheral areas generally had a greater impact on the border cities, contributing around 15.3% to 57.5%, and had a less impact on the central cities with the contribution lingering around 0.3% to 8.4%. The source contributions of PM_2.5 were greatly affected by near-surface wind field, and showed obvious regional transmission characteristics. Residential, industrial and transportation sources contributed significantly in these 28 cities, with contribution percentages ranging from 26.6% to 45.8%, 16.4% to 37.8% and 13.0% to 35.9%, respectively. This study showed that RegAEMS could be used to perform the analysis of the regional and industrial sources of fine particulate matters in cities and had great application potentials in the scientific management and control of atmospheric pollution.