交通与气象因子对不同粒径大气颗粒物的影响机制研究

为了研究北京市气象因子与车流量、车速等交通因子对PM2.5、PM10浓度水平的影响,在市区三环主路及居民区选取了28个采样点,采集滞尘量,PM2.5、PM10浓度、车速、车流量、温度、湿度、风速等数据.通过3个月的滞尘质量分析,得出交通源对空气质量的影响是显著的,其中三环主道路两侧采样点和远离交通源对照点滞尘均值分别为0.284 g和0.016 g.再由道路口与居民区对比实验(局部实验)得出,居民区采样点测得的PM2.5和PM10浓度均低于道路口颗粒物浓度,差值均值分别为101 074 n·(cf)-1和15 386 n·(cf)-1,同时PM2.5白天浓度一般低于夜间.最后结合最佳子集预测模型分析得出,PM2.5和PM10受到湿度和温度的影响最大,车速、车流量、风速次之,其中车速、车流量、低风速对颗粒物PM2.5的影响比对PM10的影响更为显著.

Study on Influence of Traffic and Meteorological Factors on Inhalable Particle Matters of Different Size

To study the effects of meteorological and traffic factors on the PM_2.5 and PM₁₀ concentrations, 28 samples were taken in the Third Ring Road of Beijing, and dust fall weight, velocity of vehicle, traffic volume, temperature, humidity, wind speed, PM_2.5 and PM₁₀ concentration data were collected for these samples. Analysis of the collected data on dust fall weight indicated that the traffic had a significant impact on the air quality. The average dust fall weights in the road and away from the traffic source were 0.284g and 0.016 g, respectively. The results of the partial experiment indicated that concentrations of PM_2.5 and PM₁₀ in residential areas were lower than those in road, furthermore, the PM_2.5 at night was often higher than that during daytime, and the mean values of the difference in PM_2.5 and PM₁₀ were 101074 n·(cf)^-1 and 15386 n·(cf)^-1, respectively. Through analysis using the best subset prediction model, it was indicated that PM_2.5 and PM₁₀ were both most significantly influenced by temperature and humidity, followed by wind speed, velocity of vehicle and traffic volume. Comparing with PM₁₀, the velocity of vehicle, traffic volume and wind speed had a more significant influence on PM_2.5.