Análise de ilhas de calor da Floresta Nacional de Brasília e seu entorno utilizando imagens de satélite Landsat 8

Abstract

With the rural exodus in the 20th century, Brazil, whose population was concentrated mainly in rural areas, began to receive large numbers of people in urban centers. Vegetations, rivers and natural areas suffered significant impacts with the disorderly urban growth. With the high degree of urbanization, cities begin to suffer from a climatic phenomenon called Heat Islands, where the average temperature in cities is higher than in rural areas. Thus, the objective of this work was to analyze the formation of Heat Islands in the National Forest of Brasília and in its urban surroundings, comparing the temperatures of both and verifying the influence that the forest exerts on its surroundings. Therefore, the TST algorithm was used to estimate the land surface temperature from Landsat 8 satellite images. The forest and its surroundings were classified by land use and occupation. They are: Dense Urban Area, Non­Dense Urban Area, Farms, Pasture, Gallery, Eucalyptus, Pinus, Murundum, Cerrado and Vereda. After analyses, the land occupation class that obtained the highest average temperature was the Dense Urban Area, with 35°C in the summer season and 28.3°C in the winter. While the lowest average temperature was in the Pinus areas, with 25.2°C in summer and 22.6°C in winter. This TST difference is due to the characteristics of each use. Vegetation areas have greater energy reflectance power, while built areas retain more energy and, consequently, present the formation of Heat Islands. Through the study of Heat Islands, it was possible to verify the importance of the forest in a context of rising urbanization, in addition to the risks of increased temperature for the health and quality of life of residents.