Study On The Dispersion Model Of Vehicle Exhaust Pollutant In Street Of Chengdu

In recent years, the motor vehicle recoverable amount in Chengdu increases fast continuously. By the end of March this year, the motor vehicle recoverable amount in Chengdu has already been up to 1,830,000, and still increase progressively at the speed of 800 for every day. The quantity of motor vehicle increasing constantly causes the emission of urban motor vehicle pollutant to increase year by year. The tail gas of motor vehicle pollutes the primary pollution source that has already become urban atmosphere.It's a complicated process for the vehicular exhaust to disperse in street canyon. Many factors may affect this process such as the source intensity, meteorological factors and street geometry and so on. Some typical streets are selected as the objects of the study. Then the characteristics and the current situation of vehicle emission in Chengdu are explored. Emphasis is put on how the meteorological factors and street geometry affect the dispersion process of the vehicular pollutants in streets. CALINE4 is selected to simulate the dispersion process of the vehicular exhausts in the streets according to the characteristics of the meteorological conditions and street geometry in Chengdu city. The author used the model to simulate the motor mobile pollution. The result shows that the CALINE4 model and set up a parameterize plan. The modeled value of the modified CALINE4 and the measured value show good pertinence. The precise rate of the result is been improved.Finally, the author gives some advices to reduce the motor ca pollution. The results of this study have obvious scientific value and practical value to support the decisions of the government with scientific data.