Estimating Emission Loads from Road Transportation in Kathmandu Valley

Abstract

Kathmandu Valley which was previously known as city of temples have now transformed into a city of pollution. Dust resuspension due to motor vehicles is the major source of air pollution. The department of environment, in 2017, find out that the transport sector contributed to 28% of pollutants in Kathmandu valley. Emission loads can result in serious health issues like heart diseases, COPD, respiratory syndromes etc. The study looked at the increasing tendency in the evolution of various vehicle types, their energy use and associated environmental pollutants in the Kathmandu valley. The number of vehicles registered each year in the Kathmandu valley were collected from the Department of Transport Management situated at Ekantakuna in Lalitpur district and Department of Transport Management situated at Gurjudhara in Kathmandu district. The majority of vehicles registered in the valley were motorbikes which comprised about 78.28 % of total vehicles registered in Kathmandu valley followed by 13.97 % composed by car/jeep/van type of vehicles. Microbus were seen to be registered lowest, comprising only 0.35% of total number of vehicles registered in Kathmandu valley. Since the annual vehicle scrap data was lacking, the concept of vehicle survival was used to simulate the evolution of actual vehicles on the road. The vehicle's life cycle profile was mixed with the Weibull distribution function for this. The estimated vehicle energy demand and emissions were calculated using these predicted vehicle numbers. The total emission load in 2020 was 2.7 million tons/year for CO2, 101 thousand tons/year for CO, 12 thousand tons/year for NOx, 20 thousand tons/year for HC and 5 thousand tons/year for PM10 approximately. The study has predicted the CO2 emission in the valley for 2025 and 2030 years as 4.5 million tons and 6.4 million tons, respectively. The study shows that people preferred private vehicles in comparison to public vehicles ultimately increasing the fuel requirement for travelling the same distance.