Analysis of the vehicle fleet in the Kathmandu Valley for estimation of environment and climate co-benefits of technology intrusions

作者：Shrestha Shreejan Ram; Nguyen Thi Kim Oanh^*; Xu Quishi; Rupakheti Maheswar; Lawrence Mark G

来源：Atmospheric Environment, 2013, 81: 579-590.

DOI：10.1016/j.atmosenv.2013.09.050

• Emission inventory
• Traffic
• High emitter
• BC
• Climate co-benefit
• Kathmandu

Technologies and activities of the on-road traffic fleets, including bus, van, 3-wheeler, taxi and motorcycle (MC) in the Kathmandu Valley, Nepal, during 2010, were investigated with the aim to produce emission estimates, using the International Vehicle Emission (IVE) model, for the base year and for an optimistic technology scenario. The parking lot survey, GPS monitoring and video camera monitoring were conducted over four typical road types (arterial, highway, residential and outskirt roads). The average age of vehicles in the bus, van, 3-wheeler, taxi and MC fleet was 9, 8.7, 11, 9.5 and 4 years, respectively. There were some extremely old buses (over 40 years old) which had extremely high emission factors. Except for MCs that had a large share of Euro III technology (75%), other types of surveyed vehicles were at most Euro II or lower. The average vehicle kilometers traveled (VKT) for each vehicle type was estimated based on odometer readings which showed comparable results with the GPS survey. The emission factors (EFs) produced by the IVE model for the driving and meteorological conditions in Kathmandu were used to estimate emissions for the base case of 2010. EFs in Kathmandu were higher than other developing cities, especially for PM and NOx from the bus fleet. Diurnal variations of the emissions were consistent with the diurnal vehicle density. From the fleet in 2010, total emissions of the major pollutants, i.e., CO, VOC, NOx, PM, BC, and CO2, were 31, 7.7, 16, 4.7, 2.1, and 1554 Gg, respectively. If the entire fleet in the Kathmandu Valley would comply with Euro III then the emission would decrease, as compared to the base case, by 44% for toxic air pollutants (excluding CO2) and 31% for climate-forcers in terms of the 20-year horizon CO2-equivalent Future surveys should include other vehicle types such as trucks, personal cars, and non-road vehicles. The EFs obtained for the Euro III scenario in Kathmandu were well above those in other parts of the World, hence strongly suggesting influences of the driving conditions, especially the low vehicle speeds, on the vehicle emission in the valley.

• 出版日期2013-12