The application of GIS to air quality analysis in Taichung City, Taiwan, ROC

This paper presents a preliminary study for the evaluation of transport-related air pollution situations in an urban area. The authors utilize a geographic information system (GIS) which integrates a vehicle emission model, pollutant dispersion model, backward trajectory model and related databases to estimate the emissions and spatial distribution of traffic pollutants in Taichung, Taiwan, ROC. The model not only can analyze the current pollution situations, but also can predict the emissions influenced by changes in specific traffic conditions or management policies. The results show that there are higher CO emissions around downtown areas in Taichung City, and the areas along Highway No.1 sustain higher NOx, SOx and TSP pollutions. Although the segment length of Highway No.1 within Taichung City is not very long, it contributes a significant portion of total suspended particulate (TSP), nitrogen oxides (NOx), and sulfur oxides (SOx) emissions to this area. Furthermore, predictions of several hypothetical scenarios indicate that the major effect of upgrading motorcycles is the reduction of TSP emission by more than 10%, while increasing average traffic speed of city roads may reduce more than 14% of CO emissions.