A alteração no regime de fogo devido à ação humana é a principal ameaça à biodiversidade do Cerrado Brasileiro e tem levado a iniciativas de melhores políticas públicas ambientais. Neste contexto, a disponibilidade de informações confiáveis sobre as distribuições espacial e temporal de áreas queimadas afigura-se crucial, não só para uma melhor gestão dos recursos naturais, mas também para estudos da química da atmosfera e de mudanças climáticas. O sensoriamento remoto via satélites constitui, neste âmbito, uma ferramenta indispensável na medida em que permite um monitoramento especialmente útil em áreas extensas e/ou de difícil acesso afetadas pelo fogo Neste contexto, este trabalho visa aprimorar o conhecimento científico sobre o fogo na vegetação do Cerrado, especificamente através da avaliação de qual índice espectral tem o melhor desempenho na discriminação de áreas queimadas em imagens Landsat TM. Foram avaliados dez índices espectrais: Burned Area Index (BAI), Char Soil Index (CSI), Enhanced Vegetation Index (EVI), Normalized Burn Ratio (NBR), variation of Normalized Burn Ratio (NBR2), Normalized Difference Vegetation Index (NDVI), Normalized Diff erence Moisture Index (NDMI), Mid-Infrared Burn index (MIRBI), Soil Adjusted Vegetation Index (SAVI) e W-burn-sensitive vegetation index (W). O índice M de separabilidade foi utilizado para avaliar a eficácia de cada um dos índices espectrais em discriminar pixels queimados e não queimados. Os resultados mostram que os índices que utilizam os canais infravermelho de ondas curtas (banda 5 e banda 7), possuem maior capacidade de separabilidade de áreas queimadas na região deste estudo.

Studies carried out have revealed that every day around three thousand people lose their lives in the world due to traffic accidents and poor air quality. Large cities, with their millions of inhabitants and vehicles, face many problems relating to vehicular traffic. In 2015, the speed limit was modified on several roads in the city of São Paulo, Brazil. However, in 2017, the speed limits were increased again, but not on all previous routes. This study analyzed the impact of this change on the number of accidents and pollutant concentrations, over a period of ten years, comparing the periods before and after the implementation of the measure, using real data collected and provided by the authorities of the city and the state transit and environmental companies, on more than forty routes and two nearby air-quality stations. The results showed a clear reduction in the number of accidents without victims on the roads of the city of São Paulo, starting in 2010. Although the restrictive measures imposed by government officials may have contributed to the decrease in the number of accidents, the number of fatalities has not changed so much. Air pollution has not improved substantially with speed changes, as new speed increases have been linked to new episodes of congestion. The average number of fatalities due to accidents has been increasing since 2010 and accidents are becoming more serious. The application of a general linear statistical model (GLM) estimated the impact of the speed reduction policy in terms of the number of injuries avoided per month: 43.4 and 14.1 on other roads and on the Pinheiros highways, respectively. The results highlight the need for a constant data collection by the authorities in cities with high vehicle traffic. The important temporal time trend in terms of reduction of injuries, but not in terms of fatalities and air quality, shows the need to apply joint public policies, not only speed reduction, but also the use of new technologies and raising drivers’ awareness of the problem.

Studies carried out have revealed that every day around three thousand and twelve people lose their lives in the world due to traffic accidents and poor air quality. Large cities, with their millions of inhabitants and vehicles, face many problems relating to vehicular traffic. In 2015 the speed limit was modified on several roads in the city of São Paulo-Brazil. However, in 2017 the speed limits were increased again, but not on all previous routes. This study analyzed the impact of this change on the number of accidents and pollutant concentrations, over a period of ten years, comparing the periods before and after the implementation of the measure, using real data collected and provided by the authorities of the city and the state transit and environmental companies, on more than forty routes and two nearby air quality stations. The results show a clear reduction in the number of accidents without victims on the roads of the city of São Paulo starting in 2010. However, the restrictive measures imposed by government officials may have contributed to the decrease in the number of accidents, but the number of fatalities has not changed much. Air pollution has not improved substantially with speed changes, as new speed increases have been linked to new episodes of congestion. The average number of fatalities due to accidents has been increasing since 2010 and accidents are becoming more serious. The application of a general linear statistical model (GLM) estimated the impact of the speed reduction policy in terms of the number of injuries avoided per month: 43.4 and 14.1 on other roads and on Pinheiros marginal, respectively. The results highlight the need for a constant data collection by the authorities in cities with high vehicle traffic. The important temporal time trend in terms of reduction of injuries but not in terms of fatalities and air quality, shows the need to apply joint public policies, not only speed reduction, but also the use of new technologies and raising drivers’ awareness of the problem.