Historical urban growth, land surface temperature dynamics, and future land use and land cover projections in the Metropolitan Region of Vale do Aço

Abstract

Changes in Land Use and Land Cover (LULC), especially those associated with the urbanization process, play a fundamental role in intensifying phenomena such as heat islands. These are characterized by the temperature difference between urban areas, affected by anthropogenic activities, and their rural surroundings, which are less impacted. The Metropolitan Region of Vale do Aço (RMVA), located in the interior of Minas Gerais, Brazil, lacks studies addressing the relationships between urban climate and landscape dynamics. The objective of this study was to analyze the spatiotemporal dynamics of LULC between 1985 and 2024, project scenarios for 2045 and 2065, and evaluate the relationships between Land Surface Temperature (LST), different land cover classes, and the vegetation (NDVI), built-up area (NDBI), and moisture (NDMI) indices, focusing on the formation and intensity of Surface Urban Heat Islands (SUHI). MapBiomas data and Landsat 5 and 8 satellite images were used to estimate LST and SUHI. The results revealed important landscape transformations throughout the analyzed period: natural vegetation decreased by 26% between 1985 and 2024, while forest plantation areas increased by 850.21%. Urban areas also exhibited substantial growth, reaching 54.75%, with the potential to increase by an additional 52.56% in the projected scenarios between 2024 and 2065. Correlations between LST and spectral indices were stronger during the rainy season, especially in agricultural and pasture areas. The spatial intensity of SUHI was more diffuse during the rainy season and exhibited a smaller spatial extent during the dry season, highlighting the possible influence of precipitation on thermal variation.