Morphometric characteristics and implications in sediment accumulation in reservoirs: the case of Hedberg dam, Ipero/SP/Caracteristicas morfometricas e suas implicacoes no acumulo de sedimentos em reservatorios: O caso da represa Hedberg, Ipero/SP

• Published in: Ra'e ga 2016-04 (36), p.225
• Main Authors: Silva, Darllan Collins da Cunha, Sales, Jomil Costa Abreu, Filho, Jose Luiz Albuquerque, Lourenco, Roberto Wagner
• Format: Article
• Language: Spanish
• ISSN: 1516-4136

Sediments resulting from erosion are a silting major contributor, in many cases, causing aquatic environments eutrophication. Thus, this study evaluated spatially the degradation degree of a reservoir, by physicochemical evaluation, limnological, as well as hydrological and hydraulic modeling, aiming the problem characterization and diagnosis as a subsidy tool to mitigating actions. The results showed that the water reservoir has a substantial water volume around 500,000 [m.sup.3] and a 2.28 perimeter development index, indicating a margins moderate irregularity degree. The reservoir bottom relief showed the deepest areas in the guidance of west-central to northeast and from northeast to north, being the deepest region is around 120 m from the dam, with average and maximum slope of approximately 30% and 52%. The limnetic and coastal region conductivity and temperature were above the tolerance levels suggested by the environmental agency indicating a large amount of dissolved ions, which may come from sewage or soil erosion. It was also possible to identify the algae and macrophytes proliferation, which may indicate the presence of hypertrophication process. For the qualitative improvement of the reservoir, dredging interventions and restoration of riparian vegetation in the dam surroundings areas should be performed, thus improving water quality conditions. The methodology proved to be very efficient to quantify sediment in reservoirs and great relevance to managing programs development and reservoirs management. Keys words: Erosion; water quality; sediments; reservoirs. Sedimentos resultantes de processos erosivos sao um dos principais responsaveis pelo assoreamento e, em muitos casos, eutrofizacao de ambientes aquaticos. Desta forma, o presente estudo avaliou espacialmente o grau de degradacao de um reservatorio, por meio da avaliacao fisico-quimica e liminologica, bem como por modelagem hidrologica e hidraulica, visando a caracterizacao e o diagnostico do problema como ferramenta de subsidio a acoes mitigadoras. Os resultados obtidos mostraram que o reservatorio tem um volume hidrico aproximado de 500.000 [m.sup.3] e um indice de Desenvolvimento de Perimetro de 2,28, indicando um grau mediano de irregularidade das margens. O relevo do fundo do reservatorio apresentou as maiores profundidades na orientacao de centro-oeste a nordeste e de nordeste a norte, estando a regiao mais profunda a cerca de 120 m da barragem e declividade media e maxima de aproxima