SOURCE CONTRIBUTIONS TO AMBIENT CONCENTRATIONS OF CO AND NOX IN THE URBAN AREA OF BEIJING

Abstract

An emission inventory based on GIS technology was developed in this study, and used to estimate the spatial distribution of the stationary and mobile sources in the urban area of Beijing. The stationary sources were divided into various types of finer classes depending on different usage, stack height and emission factors. The mobile sources were treated as both line sources and area sources. It was shown that total anthropogenic CO and NO_X emissions had reached 1.4 million and 233 thousand tons, respectively, and vehicle sources emissions of CO and NO_X accounted for 76.8% and 40.2%, respectively, of the total emissions in 1995. ISCST3, a Gaussian dispersion air quality model, was modified at low wind speed condition, and then used to facilitate the study of source contributions to ambient concentrations of CO and NO_X in Beijing. The simulation results showed that emissions from the vehicle sources had contributed 76.5% and 68.4% of the total CO and NO_X concentrations in urban atmosphere of Beijing in 1995, and were even higher in the city core (86.3% of the CO and 72.0% of the NO_X). Therefore, strategies for CO and NO_X pollution control will of necessity need to focus on the vehicle sources.

Keywords:

• Air quality
• Beijing
• ISCST3
• Vehicle emission
• Source contributions

ACKNOWLEDGMENTS

The funding for this research was supported, in part, by the Ford China Research & Development fund.