Geotecnologias aplicadas ao estudo comportamental das ilhas de calor urbanas

Abstract

The urbanization process can alter the physical space and influence the environmental quality to the detriment of the reduction of green areas present in large urban centers. As a consequence, many cities are impacted by the effect of heat islands, a phenomenon responsible for the accumulation of heat inside urbanized areas, generating a considerable increase in temperature, which can influence the quality of life of the population. In this context, the aim of this study was to analyze the spatial and temporal distribution of urban heat islands and the influence of green areas on the formation of urban microclimates in the city of Rio de Janeiro, Brazil. The methodological procedures employed were divided into the following steps: a) analysis of changes in land use and occupation between the years 2014-2018; b) seasonal estimate of the earth's surface temperature (Ts); c) obtaining and geostatistical seasonal comparison between the vegetation indexes (NDVI and EVI), constructed area (NDBI) with the temperature of the terrestrial surface; ecological assessment of heat islands using the index (UTFVI); estimate of the level of urban thermal comfort using the indices (ITU, IDT and TEV). As a result, it was observed that the city of Rio de Janeiro is under the influence of the heat islands, the oldest and most urbanized areas of the city are the most affected by high temperatures. It was possible to verify the role of vegetation in the formation of urban microclimates through the negative correlation coefficient between the surface temperature (Ts) and the vegetation indices (NDVI) and (EVI), and also a positive correlation coefficient between Temperature of Surface (Ts) and the Index of Areas Built by Normalized Difference (NDBI), demonstrating the influence of urbanization on the increase in temperature. Through the comfort indexes analyzed, it was possible to infer that, especially during the summer, the thermal sensation perceived by the population reaches very uncomfortable levels, demonstrating the need and importance of adopting mitigation measures to reduce the temperature. Thus, it is concluded that changes in the pattern of land use and occupation due to constant urbanization directly impact the formation and intensity of heat islands, with vegetation acting positively in the control of the urban microclimate. The methodology employed presents potential for the behavioral study of urban heat islands to other cities in the world.