Estudo numérico do impacto da frota veicular na qualidade do ar na região metropolitana de Porto Alegre

Abstract

Many economic sectors in Brazil have developed and transformed in recent years, which has now diminished by the unfavorable situation in the economy. In most cases, the economic growing affects the environmental pollution. One of the sectors where more changes have occurred and that greatly influences pollution, specifically air pollution, is transport; despite that, studies in Brazil are insufficient to estimate the pollution tendency associated with this sector, important to mitigation police. This investigation aim to the study of the vehicle fleet impact on air quality in the Greater Porto Alegre (GPA). The models-system CCATT-BRAMS (Coupled Aerosol and Tracer Transport model to the Brazilian Development on the Regional Atmospheric Modeling System) was used to perform the simulations and the PREP-CHEM-SRC (Preprocessor of tool trace gas and aerosol emission fields for regional and the global atmospheric chemistry models) for emission inventories that serve as inputs to the model. The base year for analysis was 2009 and the scenarios are constructed until 2030. In order to complement global emissions information, they were created pollution emission scenarios associated with the evolution of the vehicle fleet in the study region using linked information such as total current fleet and new licenses in GPA, in addition to emission factors and intensity of use of different vehicles. The results show a decrease in emissions of CO, NMHC and NOx in 2030 compared to 2009 base year, related to the vehicular activity. This decrease was caused mainly by the renewal of technology fleet and the implementation of emission control programs created by the government. This reduction in the emissions caused a decreasing in the NOx average concentrations estimated for 2030 (decreasing of between 40 % and 60 % in relation to the base year) and an increasing in the O3 average concentrations of at night and morning (up to 40 %) and decline of this species in afternoon and early evening (up to 20 %). It was also possible to observe the influence of reduced emissions in GPA on levels of O3 and NOx in the neighboring areas, demonstrating the strong impact of major urban centers in the towns and surrounding areas.