Processos erosivos em encostas da área urbana: o caso do Morro do Urubu.

Abstract

Erosive processes on slopes in the urban area: the case of Morro do Urubu. The main goal of this research is to identify the causes of erosive processes at the slope area the Morro do Urubu community is located, looking to identify possible slip risk situations, considering the social vulnerability level. From the late 21th century onwards, Brazil begins to see a demographic explosion process, bringing along a variety of problems, such as: exclusion of the poor population and consequent occupation of areas that are improper for habitation, this being a result of real estate speculation, which overestimates central areas with flat topography, leaving the hillside and the riverside as viable options - financially speaking - to the disadvantaged citizens. When it comes to the slopes, the occupation of these areas generally occurs in an unordered way and with no previous planning, the anthropic modifications for the use and occupation of these spaces will drive erosive processes in the soil and, as a consequence, there will be risk to the population occupying the area due to the natural dynamics change of the site, creating the landslide risk areas. The theoretical basis used were the existing works of the authors on: urban expansion in Brazil (FERREIRA et al., 2008) (MAIA, 2010), (RIBEIRO, s/d), (SANTOS; SILVEIRA, 2010); the concepts of risk (CARVALHO, 2011), erosive processes (GUERRA, 2008), anthropic actions at urban slopes (GIRÃO; CORRÊA; GUERRA, 2007). Considering the work of Girão, Corrêa and Guerra (2007), the methodological way adopted was the identification of anthropic causes and processess directly related to the instability of urban slopes. The methodological procedures used in this work was based on the literature review on the subject and the use of satellite images for elaborating thematic maps. This work originated from a research under the Scientific Initiation Volunteers Institutional Program - PIVIC, using the theme as the subject of monograph study. Based on this research, it was possible to verify: the pluvial erosive processess are present at the Morro do Urubu community in a variety of intensities, caused by anthropic action. However, the landslide risk is low, due to the soil's low depth. The community shows various shortages which has been ignored by the public government for many years.