[Vehicle Exhaust Emission Characteristics and Their Contributions in Jiangsu Province]

An hourly vehicular emission inventory with 1 km×1 km resolution was developed for Jiangsu Province in 2015, using the COPERT model and ArcGIS technology. The improved "standard road length" method, as well as road network information and monthly, weekly, and daily variations of the congestion delay index were used to increase temporal-spatial resolution. The contributions of different vehicle types, emission standards, and road types to total vehicular emissions were analyzed. Results showed that vehicular emissions of NO, HC, CO, PM_2.5, SO₂, OM, and BC were 490.9, 166.3, 1614.8, 16.9, 1.9, 3.6, and 6.7 thousand tons, respectively. On average, Suzhou and Xuzhou contributed 34%-45% of the total. Evaporative emissions of HC were 20.2 thousand tons, accounting for 12% of total HC emissions. Small passenger cars and motorcycles were the major HC and CO contributors, accounting for over 30% of total emissions. Heavy-duty diesel trucks contributed 36%-54% to NO, PM_2.5, SO₂, OM, and BC emissions, representing much higher emissions than other vehicles. Heavy-duty and medium-duty diesel trucks in Suzhou and Xuzhou are the main sources of NO and PM_2.5emissions. China Ⅲ diesel vehicles account for the largest share (42%-55%) of NO, PM_2.5, SO₂, and BC emissions. China Ⅲ heavy-duty diesel trucks and China 0 medium-duty diesel trucks are the primary and secondary contributors of NO, PM_2.5, OM, and BC emissions, with a total share of 40%-56%. China 0 motorcycles contributed about 16% to total HC and CO.