广州市高架路两侧PM2.5分布特征研究

Study on Distribution Characteristics of PM2.5 on Both Sides of Guangzhou Elevated Road

针对广州市琶洲大桥北段高架路,本文通过实测分析了高架路两侧PM2.5质量浓度的分布特征,解析了车流量、车型比例、风速风向、温湿度等因素对PM2.5浓度变化的影响,同时建立了高架路机动车尾气排放与扩散模型,并通过模拟值与实测值的对比阐明了误差原因。结果表明:在水平方向上,PM2.5浓度随着与高架路面距离的增加而减小,在垂直方向上,PM2.5浓度随着垂直高度的下降先升高后降低。影响因素分析表明,车流量影响较小,而货车比例、风速风向、温湿度对于PM2.5浓度分布的影响较大。利用实测数据验证了高架路机动车尾气排放与扩散模型能够较好地预测高架路PM2.5浓度的空间分布特征。

According to the northern section of Guangzhou Pazhou Bridge,this paper analyzes the distribution characteristics of PM2.5 concentration on both sides of the elevated road,and analyzes the influence of vehicle flow,vehicle proportion,wind speed and direction,temperature and humidity on PM2.5 concentration. At the same time,the vehicle exhaust emission and diffusion model of the elevated road was established,and the reason for the error was clarified by comparing the simulated value with the measured value. The results show that in the horizontal direction,the PM2.5 concentration decreases with the increase of the distance from the elevated road surface. In the vertical direction,the PM2.5 concentration increases first and then decreases with the decrease of the vertical height. The analysis of influencing factors shows that the influence of vehicle flow is small,but the proportion of trucks,wind speed,temperature and humidity have a great influence on PM2.5 concentration distribution. Using the measured data. It is verified that the exhaust emission and diffusion model of the elevated road vehicle can better predict the spatial distribution characteristics of the PM2.5 concentration of the elevated road.