Resumo:
Due to the combination of extreme precipitation and/or rainfall for consecutive days in
landscapes dominated by plains and narrow valley bottoms, large areas of the Brazil southeast
and south regions are naturally susceptible to flooding. The Ribeirão José Pereira sub-basin,
located in the south of Minas Gerais, more specifically in the municipality of Itajubá-MG, is
one of these areas, suffering from floods aggravated by interventions in the natural course of
the stream. In a great lack information context about the vulnerability of the population exposed
to risk, the present work aims to analyze this aspect through the development and spatialization
of a socio-environmental vulnerability index for the sub-basin studied. The methodological
procedures consisted of: literature review and georeferenced data collection; thematic maps
elaboration of the variables, using geoprocessing; influence evaluation of flood conditioning
factors on flood susceptibility, applying the AHP (Analytic Hierarchy Process) method;
influence evaluation of social, economic and demographic indicators on social vulnerability,
through the AHP method; variables aggregation and preparation of final maps; and results
analysis. The final socio-environmental vulnerability map to floods showed that 87.46% of the
sub-basin has very low/low vulnerability, 10.09% medium vulnerability and 2.48% high/very
high vulnerability. The results showed concentration of high vulnerability areas in the urban
perimeter, where there is a high percentage of soil sealing and the highest population density
indices. The study of the sub-basin social indicators, in turn, showed a trend towards rural areas
with high social vulnerability, while it evidenced the existing social differences in the urban
perimeter of the sub-basin. It is understood, therefore, that the developed index can provide
information at the local and regional level of the populations that need more attention from the
public authorities, either because they are in a socioeconomic vulnerability situation, or because
they present a high degree of exposure to flood risks.
