Thesis (M. Sc.) - Asian Institute of Technology, 2011

A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Environmental Engineering and Management.

Kathmandu Valley air quality is declining day by day and vehicles are one of the major sources of air pollution in the Valley. Proper understanding of vehicle emission in the valley is important part to analyze the issues of air pollution. The purpose of this study is to develop an emission inventory of transportation fleet in Katlunandu valley, and analyze various technology scenarios to reduce the emission. The International Vehicle Emission (IVE model) is used in the study to generate the emission inventory for current fleets and project future emission inventory in 2020 under different engine and fuel technology scenarios. The emission changes in the scenarios were compared with the base year emission (2010) and future emission under business as usual (BAU) for the both air pollutants and climate forcing agents (green house gases, and aerosol). Data on local fleet and driving patterns in the valley were collected using a questionnaire survey (700 respondents) and OPS survey. This study incorporated public vehicles such as bus, taxi, van, 3-wheelers and a motorbike as a private vehicle. The emission of the base year 2010 in tonne per year for Carbon monoxide (CO) 17696, Volatile organic compound exhaust (VOC) 4382, Volatile organic compound evaporation (VOC evap) 575, Nitrogen dioxide (NOx) 1797, Sulphate (SOx) 30, and Particulate Matter (PM) 521. The Green House Gases (GHG) emission in tonnes per year is 326408 for Carbon dioxide (C02) , 1.9 for Nitrous oxide (N20) and 896 for Methane (CH4).The emission under BAU in 2020 and for 3 engine technology and 3 fuel technology scenarios were comparatively analyzed. Under the BAU scenario the emission in 2020 will increase by 50% of total criteria pollutant except Particular Matter that is decreased by 50% and increased by 24% of climate forcers in terms of 20 years Global Warming Potential (GWP) horizon. The fuel technology changes appeared to bring in more co-benefits in emission reduction for both air pollutant emissions and climate forcers. The change in fuel is yet considered in the government plan and policy hence scenario 1 i.e. change in motorbike engine technology, is recommended by this study to improve air quality in the valley and gain climate co-benefit.