The Study On The Characteristics Of CO Pollution Of Motor Vehicle Emissions In Typical Urban Road

It is an indisputable fact that the increasingly rapid development of modern economy and technology has brought people not only unprecedented prosperity of both material and spiritual return but also some trouble. Just as air pollution of on-road motor vehicle emissions in urban roads. In urban environments, traffic emission has been the most important sources of air pollution. As a result of the increase of motor vehicular population, air pollution related with traffic exhaust has been getting worse in citis. Air quality monitoring studies conducted near major roadways have detected elevated concentrations compared to overall urban background levels. Fortunately the contribution of motorized traffic to air pollution is widely recognized and every level of society has resorted to various kinds of effective measures for controlling vehicle emissions and improving ecological environment and living standard. This is the main task for urban construction and certainly research background of this diploma thesis.As part of the project "Air quality M&E system in urban road", in this thesis, the characteristics of CO pollution in three kinds of typical urban roads of motor vehicle emissions in Beijing and Guangzhou were studied in detail. At the same time, emission factors of vehicles and diffusion models which were suitable for different type of urban roads in Beijing were also studied. The results were summarized as follows:I. The CO pollution was rather light in both Beijing and Guangzhou, especially in Beijing. But there were different results in different types of urban roads and also at different time. In Beijng, spatially, CO concentration in crossroad was contributed by motor vehicle emissions from four forks, so here was the most polluted place. Hourly mean concentration of CO in Xueyuan Road was the lowest of the all because of openness. Timely, first, CO concentration in winter was apparently higher than that in other periods because of very cold temperature. It was a different phenomenon in Guangzhou. Spatially, CO concentration in Keyun Road was so higher that it exceeded the limits of the 2nd grade standard of the state because of horrendous traffic flow. However, there was little difference in different seasons. There were complicated factors that lead to such phenomena.The first one was traffic flow. That exactly showed the motor vehicle emission has been the main contribution to CO in cities. Second, meteorological parameters, such as wind speed, wind direction, temperature and so forth, could affect the space-time diffusion and distribution of CO.II. After examining the regionalism, time-sensitive, transportability, availability, integrity of database, flexibility and so forth, MOBILE6.2 was selected to calculate emission factor and the total quantity of CO in Beijing. And CALINE4, OSPM were also selected to calculate CO concentration in different roads. The analysis of correlation between simulated results and experimental results showed that the two diffusion models were suitable for different type of urban roads such as the selected three typical urban roads.