Estudo da suscetibilidade a inundações na bacia hidrográfica do Rio Alcântara (RJ): subsídios ao desenvolvimento de metodologias para avaliação de enchentes urbanas

• Autor(a) principal: Costa, Fabio Henrique Lima
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13467
• topic: Flood; Susceptibility; Hydrology; Morphometric; Inundação; Suscetibilidade; Hidrologia; Morfometria; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOGRAFIA FISICA::GEOMORFOLOGIA

The world today is marked by extreme natural events known as natural disasters and has hit the major cities of the world, and their effects have been heightened by the way of organizing land use. Floods and inundations represent one of the main types of natural disasters that constantly afflict different parts of the planet. Both are natural and inseparable, involving a range of interdependent processes both natural and man-made. The Alcântara river basin is inserted in this reality of the great cities of Brazil, characterized by a vigorous process of urbanization and transformation of the landscape without the respective support regarding the potentialities to the use land. This scenario of intense changes in the urban environment reveals the importance of planning policies and territorial management. The concept of charts of susceptibility is raised within the universe of geotechnical charts, because it makes possible the analysis of the occurrence of geodynamic processes conditioned by the presence of natural predisposing factors of the physical environment. The flood susceptibility of the Alcântara river basin adopts a multicriteria and integrative methodology based on matrix that aims to integrate the slope dynamics to the lands downstream of the 2nd order basins, through the use of GIS (IDW, HAND and Combiner ). Preliminary results show a median susceptibility to the set of 463 2nd order sub-basins. For the lands downstream of the sub-basins, the IDW technique was used to evaluate the behavior of the flows by leaving the sub-basins through spatial interpolation, showing the median intensity behavior of such flows after confluences and interactions. The preliminary susceptibility to flooding corresponds to the crossing between the IDW technique and the relief weight on the land downstream of the sub-basins, which reveals 29 different susceptibility possibilities with a strong tendency of the lands with a high propensity to flood development. The HAND technique allows the construction of hydrological modeling, with susceptibility tendency to very high flood due to low vertical distance to drainage (0-6 meters). The result showed that 62.3 km² of land presented such a configuration. The final integration matrix articulated the crossing of the preliminary susceptibility with the HAND model, resulting in 140 new susceptibility possibilities. The results show a high tendency of high and very high susceptibility to the development of floods. The validation of the model generated through the flood points mapped by the civil defense, show an excellent correspondence of 74% between the lands with high and very high susceptibility and the flood points