Megalópole do sudeste brasileiro em construção? Regiões metropolitanas de Rio de Janeiro e São Paulo sob uma perspectiva espaço temporal

Abstract

In the 20th century, with the accelerated process of urbanization, large metropolises and megalopolises emerged, transforming cities into true global centers of information, people, and capital flows. The concentration of populations, economic activities, and social interactions in cities brings sustainability challenges such as housing, infrastructure, basic services, food security, health, and the environment (New Urban Agenda, UN-Habitat). In Brazil, most essential services are located in metropolitan areas, where the main urban challenges and opportunities are concentrated. In this context, the present research aims to understand land cover changes in the Rio–São Paulo axis. The analysis includes the expansion of the urban footprint, population growth, and the variation of forest fragments between 1985 and 2018. Data from MapBiomas, Geographic Information Systems (GIS), and sources such as IBGE were used to measure the gravitational pull between Brazil’s two largest metropolitan regions: Rio de Janeiro and São Paulo. The results indicate similar rates of population growth; however, there was a 4.85% loss of forest area in the São Paulo Metropolitan Region (RMSP) and a 5.3% gain in the Rio de Janeiro Metropolitan Region (RMRJ). Furthermore, an inverse relationship was observed between urban expansion and forest cover, demonstrating that urban growth often occurs at the expense of green areas. The analysis of gravitational attraction between the regions, using the center of mass method, revealed that RMSP exerts a stronger pull over RMRJ. The centers of mass of the metropolitan regions followed a northeast–southwest trajectory, while the unified center of mass shifted throughout the study period (1990–2018), reflecting the influence of public policies and socioeconomic events. In more recent years (2015–2018), there was a growing attraction of the urban footprint toward RMSP. This research contributes to the understanding of the formation of this complex urban nebula in Brazil, highlighting the interdependence and mutual attraction between the country’s two largest metropolises.