北京市交通扬尘PM2.5排放清单及空间分布特征

为建立一种自下而上的交通扬尘PM_2.5排放清单方法,对北京市不同区域、不同类型道路的路面积尘负荷进行了采样和实验室分析,对各类路网的道路车流量和车辆类型进行了调查和统计,建立了北京市道路交通扬尘PM_2.5排放清单,并对其空间分布进行了分析. 结果表明:北京市城区快速路、主干道、次干道、支路和胡同的交通扬尘PM_2.5排放因子分别为(0.05±0.03)(0.09±0.05)(0.11±0.05)(0.16±0.14)和(0.27±0.20)g/(km·辆),相应各类型道路的交通扬尘PM_2.5排放强度分别为(7.21±4.66)(5.27±3.03)(3.34±1.49)(2.84±2.49)和(0.54±0.40)kg/(km·d)；郊区高速路、国道、省道、县道、乡道和城市道路的交通扬尘PM_2.5排放因子分别为(0.10±0.03)(0.50±0.33)(0.39±0.37)(0.41±0.41)和(0.65±0.31)(0.19±0.08)g/(km·辆),各类型道路交通扬尘的PM_2.5排放强度分别为(3.82±1.31)(10.00±6.58)(3.93±3.74)(1.64±1.63)(0.65±0.31)和(0.74±0.32)kg/(km·d). 北京市道路交通扬尘PM_2.5的年排放量为13 565 t,从空间分布上看,郊区交通扬尘PM_2.5年排放量、单位道路长度排放量以及排放因子均高于市区,而城区单位行政区面积的交通扬尘PM_2.5排放量高于远郊区县. 从交通扬尘PM_2.5排放的空间分布特征看,在继续加强城区交通扬尘控制的同时,应采取措施控制远郊区县公路的扬尘排放. 自下而上的交通扬尘PM_2.5排放清单提高了排放的时空分辨率,能够识别路网中高排放的区域和路段,为交通扬尘总量管理和减排目标考核提供了一种技术手段. 

Emission Inventory and Spatial Distribution of Road Fugitive Dust PM2.5 in Beijing

Abstract:In order to develop a bottom-up approach for a road fugitive dust PM_2.5 emission inventory, silt loading samples from different types of roads in Beijing were collected and analyzed in the laboratory. Based on the investigation and statistics of traffic volume and constitution of vehicle types on Beijing''s whole road network, a PM_2.5 emissions inventory from road fugitive dust was built using a bottom-up approach, and the spatial distribution was studied. The results showed that the PM_2.5 emission factors of freeway, major road, minor road, collector and alley in Beijing urban area were (0.05±0.03), (0.09±0.05), (0.11±0.05), (0.16±0.14) and (0.27±0.20)g/(km·veh) (units shown being grams per vehicle kilometer traveled), and the emission intensities for unit length road were (7.21±4.66), (5.27±3.03), (3.34±1.49), (2.84±2.49) and (0.54±0.40)kg/(km·d), respectively. PM_2.5 emission factors of expressway, national road, provincial road, county road, town road and urban road in the suburban areas were (0.10±0.03), (0.50±0.33), (0.39±0.37), (0.41±0.41), (0.65±0.31) and (0.19±0.08) g/(km·veh), while the emission intensities for unit length road were (3.82±1.31), (10.00±6.58), (3.93±3.74), (1.64±1.63), (0.65±0.31) and (0.74±0.32) kg/(km·d), respectively. Annual emission of road fugitive dust PM_2.5 was 13,5 t in Beijing. With respect to spatial distribution, annual PM_2.5 emission, emissions of unit length of road and emissions of per vehicle kilometer traveled in suburban areas were higher than those in the urban areas, while PM_2.5 emissions per unit in urban administrative areas were higher than in suburban areas. It was concluded that control measures should be taken for road fugitive dust emissions in suburban roads, and mitigation should be strengthened in urban areas. The bottom-up road fugitive dust PM_2.5 emission inventory improved temporal-spatial resolution, identified hotspot areas impacted by emissions of dust from roadways and provided a technical means for the total management and emission reduction target assessment.