研究报告

  • 王珮玮,杨道源,吴潇萌,张少君,吴烨.基于AERMOD线源模式的城市路网一次PM2.5排放扩散特征研究[J].环境科学学报,2018,38(7):2728-2734

  • 基于AERMOD线源模式的城市路网一次PM2.5排放扩散特征研究
  • Analysis of emission dispersion features of primary PM2.5 in urban road network based on AERMOD line-source mode
  • 基金项目:国家重点研发计划项目(No.2017YFC0212100);国家自然科学基金重点支持项目(No.91544222);国家重点研发计划-政府间国际科技创新合作重点专项(No.2016YFE0106300)
  • 作者
  • 单位
  • 王珮玮
  • 清华大学环境学院, 环境模拟与污染控制国家联合重点实验室, 北京 100084
  • 杨道源
  • 清华大学环境学院, 环境模拟与污染控制国家联合重点实验室, 北京 100084
  • 吴潇萌
  • 清华大学环境学院, 环境模拟与污染控制国家联合重点实验室, 北京 100084
  • 张少君
  • 康奈尔大学机械与航天工程学院, 伊萨卡, 纽约州 14853 美国
  • 吴烨
  • 1. 清华大学环境学院, 环境模拟与污染控制国家联合重点实验室, 北京 100084;2. 国家环境保护大气复合污染来源与控制重点实验室, 北京 100084
  • 摘要:机动车排放的一次细颗粒物(PM2.5)易在城市交通密集区域和高峰时段扩散积累,形成高浓度的排放热点区域,对人体健康影响显著.本研究基于本地化机动车路网排放清单,应用AERMOD扩散模型对北京市六环内区域进行线源扩散模拟,探讨城市路网一次PM2.5扩散浓度的时空变化规律与排放特征、气象条件和临时控制措施的关系.研究表明,在典型工作日的排放水平下,冬季工作日的机动车源一次PM2.5模拟浓度日均值为2.94 μg·m-3,夏季工作日为1.95 μg·m-3.两季24 h浓度变化均呈夜间浓度高于日间的特点,但两季峰值在气象条件和排放强度的双重作用下又有所区别.冬季早晚高峰峰值浓度分别为日均浓度的2.3和1.7倍,而夏季早晚高峰由于扩散条件相对较好并未明显形成一次PM2.5峰值.研究还以APEC峰会为例,评估峰会期间临时交通管控措施的影响.结果发现,在相似的季节气象条件下,APEC峰会期间机动车源一次PM2.5模拟浓度日均值较峰会前削减50.1%,凌晨5:00达到小时最大削减率66.6%.冬夏季工作日机动车源一次PM2.5扩散浓度的空间分布呈偏态分布,65%的浓度集中在30%的网格面积上.以冬季工作日为例,高浓度热点区域主要集中在各环路快速路、易拥堵主干道及省道、国道和高速路上,以上道路应成为排放控制的重点对象.
  • Abstract:Primary fine particles (PM2.5) from on-road vehicles would easily accumulate in urban traffic dense areas and peak hours, which form concentration hot spots and do a great harm to human body. Based on localized link-based vehicle emission inventory, we employed a line-source mode in AERMOD dispersion model to simulate the region within sixth-ring road of Beijing. Further, we discussed the correlation between the temporal-spatial concentration variation of primary PM2.5 in road network and emission features, meteorological conditions, temporary management measures. The results showed that daily mean concentrations of vehicular primary PM2.5 are 2.94 and 1.95 μg·m-3 in winter and summer under typical weekday emission level. Hourly concentration curves demonstrated much higher concentrations at night than during the day for both seasons. However, concentration peaks were different between two seasons under the dual function of emissions and meteorological conditions. Primary PM2.5 concentrations during morning and evening peak hours were about 2.3 and 1.7 times of daily mean concentration in winter while no evident concentration peaks were formed at those hours in summer thanks to a more favorable condition for dispersion. Taking APEC (Asia-Pacific Economic Cooperation) summit as an example to explore the effect of temporary traffic management measures on PM2.5 concentration. Our results suggested that the daily mean concentration of vehicular primary PM2.5 during APEC summit decreased dramatically by 50.1% and the maximum concentration reduction appeared at 5 am in the morning, compared with that before APEC summit under similar meteorological conditions. Additionally, a skewed spatial distribution feature was found as 65% of vehicular primary PM2.5 concentrated on 30% area of all grids. Taking winter weekday as an example, high concentration hot spots were mainly located at national and provincial highways, ring roads and easily congested main roads, which should be the target areas to implement emission control measures.

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