Four decades of urban sprawl and population growth in Teresina,Brazil

The expansion of medium-sized cities in Brazil has increased significantly since the 80–90's decades. In that period, most of the urbanization process was represented by the agglomeration of the population in the major metropolitan areas such as São Paulo and Rio de Janeiro. Nowadays, the rural-urban movement in Brazil is predominantly affecting cities with less than 1 million inhabitants, located particularly in the Center-West and in the Semiarid Northeast regions. The city of Teresina, the capital and largest city of the Brazilian state of Piauí, is one example that has shown an accelerated process of urban development. In this context, this paper seeks to discuss the urban sprawl of Teresina over the last four decades (1974–2014), associating its trends of urban expansion and population growth with their social and environmental implications. The results of our work indicate that urban sprawl in Teresina has been continuous over the years and getting faster in the 2010–2014 period. High demographic density areas are located mostly in peripheral zones, where the low-income population dominates. The population density varies across the city, and it is far from the standard proposed by the urban legislation. Thus, urbanization in Teresina is characterized by the sprawl of its municipal boundaries, intra-urban densification and verticalization, and an increase in population, especially in areas of low-income neighborhoods.