Identification and evaluation of urban flooding zones with the support of Geotechnologies, in Natal City, Northeast Brazil
Geohazard; DEM; DSM; GIS; GNSS
Urban floods motivated by heavy rains have caused significant loss of
life and economic damage in several urban areas of the world. This flooding type have
become frequent in many Brazilian cities. In Natal City, Rio Grande do Norte (RN)
State Capital, Northeast Brazil, the urbanization process over the last four decades
promoted significant soil sealing, which has reflected in numerous urban floods per
year. This study aims to identify and evaluate areas susceptible to flooding in Natal,
specifically in the region of Tirol, considering Digital Terrain Model (DTM), Digital
Surface Model (DSM) of high precision, pluvial drainage system, historical records of
flooding and hourly precipitations, in addition to reflecting the type of occupation of
urban lots in the neighborhood. Methodological approaches were conducted and
integrated into the Geographic Information System (GIS) environment, with the support
of in loco high accuracy database of Global Navigation Satellite System (GNSS) for
urban flooding analyses. The results showed that in the study area two topographic
depressions in sectors of intense commercial and social activities stand out because they
present geomorphological and anthropic characteristics highly favorable to flooding in
events of Intense precipitation. Furthermore, the results allowed the generation of a
superficial flow models with parameters of high applicability for the improvement of
projects of urban drainage systems and urban management. This study also
demonstrated that methodological approaches based on the use of Geotechnologies can
subsidize risk management plans and reduce public expenditures with more effective
works and emergency actions.