基于车速-流量模型的动态化道路扬尘清单编制方法与应用

Construction and Application of Dynamic Fugitive Road Dust Emission Inventory Approach Based on Traffic Speed-Flow Model

目前国内外关于道路扬尘排放的计算多采用美国环境保护局推荐的AP-42排放因子法,直接计算道路扬尘的年均排放总量,但其动态化程度不足,难以满足日益增长的精细化管理需求.本研究采用车速-流量模型构建高时间分辨率的道路车流量获取方法.以天津市为例,采用自下而上的方法,结合本地化的排放因子以及天津市采取的道路扬尘控制措施,借助GIS平台编制高时空分辨率的道路扬尘排放清单,精细反映天津市道路扬尘排放的时空分布特征.结果表明:(1)时间尺度上,受早晚高峰的影响,城市道路在08:00—09:00与18:00—19:00扬尘排放强度较大,13:00—14:00是白天扬尘排放强度的低值时段.(2)空间尺度上,夜间(03:00—04:00)道路扬尘排放强度的高值区域集中在高速路段,白天扬尘排放强度的低值时段(13:00—14:00)集中在城市道路中支路密集的地区,道路扬尘排放强度高峰时期(18:00—19:00)集中在各类型的城市道路.全年道路扬尘排放高值区域集中在城市支路和郊区道路.(3)天津市内六区全年道路扬尘PM_(2.5)、PM_(10)、TSP排放量分别为603、2492和12986 t,相较以往研究有所下降.从区域看,道路扬尘排放总量呈偏远郊区>环城四区>市内六区的规律.城市道路采取的洒水措施明显降低了道路扬尘排放总量.研究显示,受交通扰动影响,道路扬尘排放呈现明显的时空分布差异.

The calculation of fugitive road dust emissions mostly adopts the AP-42 emission factor method recommended by the US Environmental Protection Administration.It directly calculates the average annual total emission of fugitive road dust,which is difficult to meet the growing demand for refined management for the degree of dynamics is not enough.This study develops a new approach to obtain high-time-resolution traffic volume information by using traffic speed-flow model.Taking Tianjin City as an example,this study adopts the bottom-up method and combines Tianjin′s localized emission factors,road dust control measures of and GIS platform to compile a high temporal and spatial resolution fugitive road dust emission inventory,which can better reflect the temporal and spatial distribution characteristics of fugitive road dust emissions in Tianjin City.The results show that:(1)On the time scale,due to influence of traffic peaks in the morning and evening,the emissions of urban fugitive road dust are higher during 08:00-09:00 and 18:00-19:00,and 13:00-14:00 is the relatively low period of the daytime dust emission.(2)On the spatial scale,the high dust emission areas are concentrated in the highway at night(03:00-04:00),in areas with dense urban branch roads at noon(13:00-14:00)and in various urban roads at peak time(18:00-19:00).Annually,the high emission areas are concentrated in roads out of the city and dense urban branch roads.(3)The annual PM_(2.5),PM10 and TSP emissions of the six city districts are 603,2,492 and 12,986 t,respectively,which are lower than previous studies.The total fugitive road dust emissions are as follows:remote suburbs>four districts around the city>six city districts.Sprinkling urban roads can significantly reduce the total fugitive road dust emissions.This study shows there are significant differences in the temporal and spatial distribution of road dust emissions due to the dynamic changes in traffic volume.