Avaliação da expansão urbana e seu impacto na dinâmica de escoamento superficial de uma bacia hidrográfica urbana na cidade de Caruaru (PE, Brasil)

Urbanization causes changes in the original characteristics of land use, generating significant environmental impact due to increased waterproofing rates and disorderly occupation of urban roads. Over the last few years, the greater availability of medium and high resolution satellite images has made it possible to monitor urban expansion and its impact on the dynamics of surface runoff in river basins through Geographic Information Systems (GIS). Among the urban centers affected by high urbanization, the city of Caruaru-PE, has a growth rate higher than the Brazilian average, presenting great waterproofing of its natural soil, and as a consequence, serious problems with flooding. In this scenario, remote sensing images of the urban contribution basin from the years 2000, 2015 and 2020 were classified into five classes: green area, impervious area of lots, asphalt road, cobblestone road and compacted soil. The results showed a significant reduction in the green area and, almost in the same proportion, an increase in the impermeable area of the lots, while the other classes had few changes. The maximum surface runoff flow, estimated by the rational method, was 26% between the years 2000 and 2015, and 41% between the years 2000 and 2020.