基于移动监测的城市街谷交通相关污染物浓度时空变化研究

为更好认识城市街谷内的大气污染特征和提供城市街谷优化设计的实证参考,本文以干旱区绿洲城市乌鲁木齐市北京南路为例,采用移动监测技术,分析了城市街谷大气污染物(CO、PM2.5)的时空分布,并识别其主要影响因素。结果表明:(1)早高峰空气质量优于晚高峰;交叉路口处污染物浓度普遍较低,但苏州路立交桥下污染物浓度较高;(2)两种污染物同源,其浓度与固定站点监测数据高度相关,风向与街谷成锐角时污染物浓度较低,风速较大时污染物浓度较高,污染物浓度与车流量相关程度较低;(3)街谷两侧建筑物高度比在[1.5,2)之间,污染物浓度较低,在[1,1.5)之间,污染物浓度较高;路网密度在[12,14)之间,污染物浓度较低,[12,14)之间的道路密度能够最大程度的降低街谷内污染物浓度。

A Study on the Spatial and Temporal Changes of Traffic-related Pollutants in Urban Street Canyon by Mobile Monitoring Technology

In order to better understand the characteristics of air pollution in urban street canyon and provide empirical reference for the optimal design of urban street canyons, this study takes Beijing South Road in Urumqi city as an example to analyze the temporal and spatial distribution of air pollutants (CO, PM_2.5) in urban street canyon by mobile monitoring technology and to identify the main influencing factors. The results showed that:(1) the air quality of the morning peak was better than that of the evening peak; the concentration of pollutants at the intersection was generally low, while that under the overpass of Suzhou road was higher; (2) the two pollutants were homologous and the concentrations were highly correlated with the monitoring data from the fixed stations. The pollutant concentration was lower when the wind direction with sharp angle to the street canyon, and the pollutant concentration was higher when the wind speed being high, and the correlation between the pollutant concentration and vehicle flow was low; (3) With the height ratio of buildings on the sides of the street canyon falls between[1.5,2), the concentration of pollutants was low; with the density of road network falls between[12,14), the concentration of pollutants was low, and the road density between[12,14) can reduce the pollutant concentration in the street canyon to the greatest extent.