Vehicular emission trends in the Pan-Yangtze River Delta in China between 1999 and 2013

Emission factors from the COPERT IV model were used to determine emission inventories of CO, NMVOCs, NOx, BC, OC, PM2.5 and PM10 for Shanghai, Jiangsu, Zhejiang and Anhui between 1999 and 2013. A GIS was used to analyze the spatial distributions of vehicular pollution in the Pan-Yangtze River Delta. Vehicular pollutants (CO, NMVOCs, NOx, BC, OC, PM2.5, and PM10) emissions in all four provinces increased between 1999 and 2012. Emissions increased more slowly after 2011, and total emissions were lower in 2013 than in 2012. Emissions increased less in Shanghai than in the other provinces, and emissions in Shanghai decreased, following the enforcement of new vehicular emission standards. Emissions of NOx increased more than those of other pollutants, rising from 39,000 t in 1999 to 148,000 t in 2013. Passenger cars and motorcycles were found to be the main sources of CO and NMVOCs, and heavy duty trucks and buses were found to be the main sources of NOx, BC, PM2.5, and PM10. Emissions were found to be higher in coastal areas than in inland areas, and were found to be particularly high along the Yangtze River, Hangzhou Bay, and the area around Tai Lake.