Técnicas de geoprocessamento na Análise Microclimática da cidade de Teresina - Piauí

Abstract

The replacement of vegetation cover for built spaces has generated concerns regarding the life’s quality of the population. A recurring concern is related to the constant changes in the microclimate perceived by the generation of the heat island phenomenon. Therefore, the objective of this research is analyzing the microclimate of the city of Teresina - PI through geoprocessing techniques. The microclimatic analysis was performed from vegetation, urbanization and surface temperature analyzes through digital image processing dated August 2016. For the development of the analyzes, three indices were used: the Normalized Difference Vegetation Index ( NDVI) that is used to highlight only the city's vegetation, the Standard Difference of Construction Index (NDBI) which emphasizes urban areas (areas with concrete cover, asphalt, roofs and exposed soils), and Surface Temperature which analyzes the earth's surface temperature in Celsius degrees. The images worked came from the Landsat 8 satellite available on the Earth Explorer website of the American Geological Survey. For the image processing the free software Qgis was used being generated 8 (eight) maps from which the results of the research were inferred. The first three (3) maps show the overall result of the application of the indices in the city in full, and the last five (5) show in more detail the influence and relation between the microclimatic variables for each region of the city (north, south, east, southeast and center) showing the most critical region of each area. The study revealed that in areas with significant vegetation and a lower rate of urbanization are nicer points in terms of climatic comfort, and in contrast, much of the territory of the capital Teresina has temperatures of 35 to 39 Celsius degrees. The study also showed that Teresina has heat islands located mainly in large areas of exposed soil which reach 4 Celsius degrees apart from other neighboring areas. In view of the general results, geoprocessing technologies proved to be efficient in the production of important information for subsidies in decision making that can lead to an improvement in the quality of life of urban populations.