PREDICTION OF RUNNING EMISSION FACTORS FROM PASSENGER VEHICLES IN AN URBAN AREA USING INTERNATIONAL VEHICLE EMISSIONS MODEL AS A COMPUTATIONAL TOOL.
The ever increasing use of motor vehicles in many urban areas of the world has resulted incities over-crowded with vehicles and their air sheds highly polluted in most cases. Though Pakistan has adopted Pak-II (equivalent to Euro II) emission standards since 2009, yet their implementation has been found unsatisfactory. This is likely to result in higher vehicular emissions and their corresponding emission factors (EFs) for all vehicles types. With the aim of predicting average runningEFs for a large urban city of Pakistan, i.e. Hyderabad, the petrol fueled passenger cars were studied to calculate EFs for criteria pollutants, toxic pollutants and greenhouse gases (GHG). These average EFs based on the selected vehicles are considered to represent the majority of passenger cars in the city. The average EFs were calculated using the International Vehicle Emissions (IVE) modelwhich has been widely used in several cities around the world.The results reveal that average daily VKT was 22.29 kilometers and average vehicle speed was 29.18 kilometers per hour. Most of the driving was found to lie in the lower engine stress mode. Average running EF (in grams per kilometer) was highest for CO2(193.99) followed by CO (24.59), exhaustive VOCs (4.54) and NOx (1.19) respectively. Euro compliant vehicles produced lowest running EFs for most of the pollutants. With current findings, increased efforts are recommended to reduce vehicular emissions and their corresponding running EFs in order to improve local air quality and reduce emissions from onroad vehicles.
Air pollution,emission modeling, emission factors,IVE model, Pakistan.