Methodological proposal for evaluating the transformation of urban microclimate in medium-sized cities: a case study in the urban mesh of the municipality of Paracatu, Minas Gerais

Abstract

The suppression of vegetation to increase built up areas intensifies the effects of urbanization and causes changes in the microclimate. Therefore, this research elaborates a methodological proposal to evaluate areas with potential for the formation of urban heat islands. Satellite images were used to verify the surface temperature and NDVI index of the study area. Mapbiomas usage and occupation data were also used. The city of Paracatu, located in the Brazilian Cerrado, was chosen for the application and validation of the proposed method. We used images from the LANDSAT-5 and LANDSAT-8 satellites, which initially underwent a resampling and standardization of the pixels. Subsequently, the surface temperature and NDVI calculations were applied, and these data were compared with the use and occupation. In general, it was possible to notice that there was, in the city, an increase in the average, minimum and maximum surface temperature. The same space-spectral behavior occurred for the NDVI, which are related to changes in land use and occupation. In relation to the areas with potential formation of urban heat islands, it was noted that these, in an interval of 14 years, tripled, being possible to relate the situation with urban expansion and the presence of new subdivisions in peripheral areas. It was also noted that the areas with mitigation potential for these were not planned, especially in the most populous neighborhood of the municipality. The results obtained were satisfactory and the proposed methodology may serve as a basis for public managers in relation to measures to mitigate the urban microclimate.