Atmospheric Environment Impact Assessment Of Mobile Source And Vehicle Control Strategies In Nanjing

With the rapid development of economy and urbanization, the number of motor vehicle has been increasing significantly, which has reached to1.31million by the end of2011.The issue of vehicle pollution is becoming more and more serious. In2014, as the2nd Youth Olympic Games will be held in Nanjing, it is very important for the government to take effective measure to improve the air quality. Since the emission factors are complex and the emission load is large, it is meaningful and pressing to estimate the impact of vehicle emission on environment and make reasonable control strategies.In order to estimate vehicle emission inventory, the air quality model is used to investigate the effect of various control strategies. The main work and conclusions are as follows:Firstly, with the basic data of vehicle and traffic volume, Vehicle emission model COPERT4was used to calculate Motor vehicle emission of Nanjing,2011. The results show that annual emission of CO. VOC. NOx、PM10、PM2.5、NH3、BC、OC are99000tons.19148tons.51036tons.2636tons.2136tons.1265tons.938tons.542tons. Passenger cars and motorcycles contribute most to VOC and CO, and diesel buses, diesel trucks are the main source of PM (particulate matter) and NOx (nitric oxide). With GIS-based road length, road type, traffic flow data, population of different area, a new approach was built to allocate the vehicle emission spatially and temporally.By comparing the simulation results of two cases with and without vehicle emission, we came to know the environmental impact of vehicle. In the spring case, Nanjing was influenced by a weak high pressure, accompany with high temperature, low relative humidity, cloudlessness. Under this condition, vehicle emission can make the average concentration of CO,NO2,O3,PM2.5changed by3.22%～25.95%,0.02%～44.54%,-23.8%～7.10%,0.10%～5.39%over domain, Ozone increased in the suburbs while decreased in the down town. In the summer case, when considering vehicle emission, CO, NO2,03, PM2.5can be changed by0.19%～17.05%,0.35%～55.82%、-10.67%～7.20%0.05%～7.29%respectively.Finally, on the basis of reviewing situation and progress of vehicle emission control, four possible control strategies including "odd-and-even license plate rule","staggered office hours","retirement of yellow label cars", and "downtown restrictions", were proposed for the Youth Olympic Games,2014. By comparing these cases, the contribution rate of different control strategies was evaluated. Among the four control strategies,"odd-and-even license plate rule","retirement of yellow label cars", and "downtown restrictions" can cut down the monthly average concentration of NO2、CO、PM2.5effectively,"odd-and-even license plate rule" have the best effect that NO2、CO、PM2.5can be reduced by27.13%、8.51%、3.58%at most, while "retirement of yellow label cars " can cut down13.43%、7.60%、0.95%, and "downtown restrictions" can cut down21.23%、6.28%、1.80%, separately. Staggered office hours" has no obvious effect on the average concentration, but can shut down the peak concentration effectively.