Cobertura vegetal em microbacias urbanas: análise temporal da cobertura arbórea e temperatura de Rondonópolis, Mato Grosso (Vegetation cover in urban microbasins: temporal analysis of the arboreal cover and temperature of Rondonópolis, Mato Grosso)

Abstract

Os objetivos deste trabalho foram quantificar a cobertura vegetal presente nas microbacias urbanas de Rondonopolis-MT e relacionar com o numero de habitantes para calcular o IVC; realizar um comparativo da quantidade de cobertura vegetal nos anos de 2013 e 2017 para saber se houve deficit ou ganho de vegetacao relacionando com as variacoes da temperatura do ar. Foi realizado o levantamento da cobertura vegetal atraves do NDVI e posteriormente relacionado aos valores de vegetacao em m 2 de cada microbacia com o numero de habitantes para se obter o ICV. Ja a comparacao dos anos estudados (2013 e 2017) foi realizado tambem pelo calculo do NDVI e posteriormente extraido os valores de NDVI para cada imagem e comparado atraves da correlacao de Pearson e teste t pareado. Os valores de temperatura entre os anos de 2013 a 2017 foram comparados com os resultados do levantamento da vegetacao. Da area total estudada (7753 hectares), a cobertura vegetal representou 622 hectares, cerca de 8% do total. O ICV para a microbacia do Escondidinho foi de 2 m2/hab. A cobertura vegetal para o ano de 2013 foi de 2.500 hectares e em 2017 foi reduzida para 1.661 hectares. Ocorreu um deficit de cobertura vegetal de 839 hectares. Os resultados da cobertura vegetal de 2013 e 2017 relacionados com a temperatura, demonstraram que houve diferencas na temperatura em locais que houve perda de vegetacao, com aumento de ate 1.5°C. A cobertura vegetal exerce um importante papel na dinâmica ambiental urbana, mantendo a temperatura mais baixa, servindo como refugio para a biodiversidade e proporcionando saude fisica e mental aos habitantes. A B S T R A C T The aims of this work were the measurement of the forest cover present on the watershed of Rondonopolis-MT and relate this with the number of inhabitants to calculate the IVC; to make a comparison of the quantity of forest cover in 2013 and 2017 in order to know if there has been deficit or gain of vegetation relating them with the air temperature. It was done the survey of the forest cover by NDVI and it was later related to the data about the vegetation in m 2 of each watershed with the number of inhabitants in order to get ICV.\xa0 As to the comparison of the examined years (2013 and 2017), it was done, too, by the calculation of the NDVI and later it was extracted the values of the NDVI to each image and it was compared using the Pearson s correlation and the paired t-test. The values of the temeprature between 2013 and 2017 were compared with the outcome of the survey of the vegetation. Of the total area investigated (7753 hectares), the forest cover represented 622 hectares, about 8% of the total. The ICV to the watershed of Escondidinho was 2 m 2 /inh. The forest cover to 2013 was 2.500 hectares and in 2017 it was reduced to 1.661 hectares. There was a deficit of 839 hectares in the forest cover. The results about the forest cover of 2013 and 2017 that were related with the temperature have shown that there were differences in the temperature in places with loss of vegetation, with a temperature rise of up to 1.5°C. The forest cover plays an important role in the urban environmental dynamics, keeping a lower temperature, serving as a refuge to the biodiversity and affording physical and mental health to the inhabitants. Keywords: ICV, Geoprocessing, Watershed, Urban microclimate.