Caracterização hidrossedimentológica e estudo da qualidade dos sedimentos na bacia hidrográfica e lago da UHE Barra dos Coqueiros

• Ano de defesa: 2018
• Autor(a) principal: Oliveira, Susy Ferreira
• Orientador(a): Cabral, João Batista Pereira
• Banca de defesa: Cabral, João Batista Pereira, Santos, Fancismário Fereira dos, Lima, Claúdia Valéria de, Cherem, Luis Felipe Soares, Becegato, Valter Antônio
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Geografia (IESA)
• Departamento: Instituto de Estudos Socioambientais - IESA (RG)
• País: Brasil
• Palavras-chave em Inglês: Hidrosedimentation; Reservoir sedimentation; Heavy metals
• Área do conhecimento CNPq: GEOGRAFIA REGIONAL::ANALISE REGIONAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/8627

By building dams in a watercourse, the hydrosedimentometric dynamics of the water bodies changes. Due the reduction of transport energy, the particulate material transported starts being deposited, reducing the volume and the useful life of the reservoir. In order to take mitigating and preventive measures, it is necessary to diagnose the sectors with the greatest amount, volume and distribution of sediments in the area of influence. The general objective of this work was to evaluate the sedimentation stage, to detect the current depositional models and to evaluate the quality of the sediments, aiming at possible mitigation measures in relation to the sedimentation of the reservoir of the Barra dos Coqueiros hydropower plant, located on river Claro, between the municipalities of Caçu and Cachoeira Alta. In order to reach the proposed general objective, the physical characterization of the area of influence on the reservoir was carried out, from geological, geomorphological, slope, soil, climate, land use and vegetation cover aspects. And to determine the possible source areas related to erosive processes, the map of potential fragility and emergent fragility was generated. In order to understand the main sites of impact, hydrosedimentological studies were carried out through CSS, Turbidity and Water Transparency variables. The study of current depositional models was carried out from the study of facies. The quality of the sediments was evaluated by the heavy metals Cadmium, Nickel, Copper, Lead and Mercury. According to fragility analysis, 30% of the area is classified as medium and high fragility, demonstrating the need for planning and utilization of conservation practices in relation to the use and vegetation cover. By means of hydrosedimentological studies, it was noticed the reduction of CSS and Turbidity downstream, according to the velocity of water flow and depth analyzed in the bathymetric surveys, in which a reduction of 0.51% of the dead volume of the reservoir was observed. Depositional models that predominate are associated with silt/clayey facies for riverbed deposits, sandy facies for stream deposits and silt/clayey and sandy facies for delta deposits. Regarding sediment quality, it was verified that cadmium presented concentrations higher than the reference parameter determined for sediments by CONAMA Resolution 454/2012. In the soil, it was also verified that heavy metals were superior to the reference values of the resolution CONAMA 420/2009, that’s related to the natural formation of the soils and to the use and occupation of the earth.