Abstract

Ho Chi Minh City (HCMC), the largest city of Vietnam and the seventh city with the highest density of inhabitants in the world (3,300 persons by kilometer square) (HCMC Urban Drainage Company, 1998), is one of the cities in the world which are seriously influenced by pollution. The main sources of atmospheric pollution are vehicles (motorbikes), the industry and population. Numerical models are the only existing tools able to predict air quality concentrations and to determine the strategies of reduction of air pollution in HCMC, different scenarios were tested. The results obtained show that the wind direction is more influenced by global scale than local phenomena. The results of the simulations show that the ozone plume is 90km in length and 30 km in width at 12h00 LT. During the selected episode (8/1/2003), the zone in the South West of HCMC is the most polluted one (180ppb at midday).