04009cas|a2200409 a 4500 20260817162018.0 050499s1994 th uu|m rtt 0| a1eng d .b10063985 AIT Thesis no. EV-94-26 Shrestha, Shyam Air pollutant emission and its influence on visibility in Kathmandu Valley Bangkok : Asian Institute of Technology, 1994 110 leaves Thesis ; no. EV-94-26 A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources & Development Thesis (M.Eng.) - Asian Institute of Technology, 1994 As visibility is directly related to air pollution, visibility data were analyzed for the period of 1975-1993 in light of meteorological factors to detect the air quality trend in Kathmandu Valley. It can be concluded that the visibility in Kathmandu Valley is deteriorating most likely due to man made activities i.e air pollution emissions. Meteorological influence on annual visibility trend are not paramount. Detailed emission inventory as a function of time and space has also been made for 1992/93 to estimate the contribution of different sources on air quality deterioration in the valley. Fuelwood/biomass combustion for Total Suspended Particulate (TSP) and Carbon monoxide (CO), automobiles for Nitrogen Oxides (NOJ and Hydrocarbons (HC), and coal combustion in brick and cement industries for Sulfur Dioxide (S02) are the major sources of emission. Estimation of emission for past year (1984/85) and a future year (2002/03) were also made. It shows that per capita emission of TSP is decreasing whereas Nitrogen Oxides (NOx) and Sulfur Dioxide (S02) are increasing considerably. Annual visibility trend shows strong negative correlation with air pollution emissions, specially Sulfur Dioxide (S02) and Nitrogen Oxides (NOJ. Among the visibility reducing species, sulfate and nitrate particle are expected to be the major contributor in the visibility change in the valley and the particulate concentration in Kathmandu Valley might exceed WHO standard most of the time in recent years. Much higher particulate concentration can be expected in urban centers. As the air quality of the valley is deteriorating rapidly, it is an urgent need to establish emission regulations and control strategies. This study provides an input to the modelling work, an important tool for air quality management, and source reduction strategies. Since actual measurement of air pollution concentration are unavailable, this type of study is appropriate to detect the air quality trend and to estimate sources contribution in most of the cities of the developing countries. Pollutants Kathmandu Valley Weihan, Su, Chairperson Reutergardh, Lars Bertil, Ecamination Committee Shrestha, Ram M., Examination Committee Government of Austria, Scholarship Donor Asian Institute of Technology. Thesis ; no. EV-94-26 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B15791 .b10063985 mnait x 240409 2 951012 m a x 0 mnait mnait mnarc 20 40 Barcode : 30050003047957 CREATED : 1994-05-16 RECORD # : i10060510 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050004250394 CREATED : 1994-05-16 RECORD # : i10060522 LPATRON : 1014386 LCHKIN : 2002-11-13 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 7 TOT RENEW : 5 Barcode : 30050160055363 CREATED : 2016-11-05 RECORD # : i12975564 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 3501 3501 0 0 0 0 MAIN MAIN mnait 2026-08-17 10.00 0 AIT Thesis no. EV-94-26 30050003047957 2026-08-17 16:20:18 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 10.00 0 AIT Thesis no. EV-94-26 30050004250394 2026-08-17 16:20:18 2 2026-08-17 20 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no. EV-94-26 30050160055363 2026-08-17 16:20:18 2026-08-17 40