Itaipu reservoir limnology: eutrophication degree and the horizontal distribution of its limnological variables
Carregando...
Data
2011-11-01
Título da Revista
ISSN da Revista
Título de Volume
Editor
Instituto Internacional de Ecologia
Resumo
Os reservatórios são ambientes artificiais e intermediários entre rios e lagos, apresentando características morfométricas e hidrológicas distintas, com alta taxa de renovação da água e organizações vertical e horizontal características. A evolução desses ecossistemas depende de variáveis que atuam em diferentes escalas espaciais e temporais. A evolução da qualidade da água do Reservatório de Itaipu foi avaliada por meio da análise das variáveis físicas, químicas e biológicas e da aplicação de índices de Estado Trófico. Observou-se que as variáveis limnológicas químicas e físicas apresentaram um padrão de variação espacial (horizontal) e temporal fortemente dependente do regime hidrológico. Os efeitos da turbidez e os sólidos suspensos totais apresentaram o mesmo padrão de distribuição por zona do reservatório. A zona fluvial foi a que apresentou as maiores concentrações de nutrientes, sólidos suspensos e turbidez. Os resultados dos Índices de Estado Trófico indicaram um estado de mesotrofia para as zonas fluvial e de transição e oligotrofia para a zona lacustre.
Reservoirs are manmade habitats, intermediate between rivers and lakes, presenting distinct hydrological and morphometric characteristics, with differential mean water residence time. They also present proper vertical and horizontal organisations, and their evolution depends on several variables acting on different special and temporal scales. The water quality evolution of the Itaipu Reservoir was evaluated through the analysis of the physical, chemical and biological variables, and by the application of Trophic State Indices. We concluded that the limnological variables present a horizontal pattern of variation highly dependent upon the hydrological regime. The turbidity and total suspended solids presented the same distribution pattern in the reservoir zones. The fluvial zone had the highest concentrations of nutrients, suspended solids and turbidity. The results of the Trophic State Indices indicate a mesotrophic level for the fluvial and transition zones, and an oligotrophic one for the lacustrine zone.
Reservoirs are manmade habitats, intermediate between rivers and lakes, presenting distinct hydrological and morphometric characteristics, with differential mean water residence time. They also present proper vertical and horizontal organisations, and their evolution depends on several variables acting on different special and temporal scales. The water quality evolution of the Itaipu Reservoir was evaluated through the analysis of the physical, chemical and biological variables, and by the application of Trophic State Indices. We concluded that the limnological variables present a horizontal pattern of variation highly dependent upon the hydrological regime. The turbidity and total suspended solids presented the same distribution pattern in the reservoir zones. The fluvial zone had the highest concentrations of nutrients, suspended solids and turbidity. The results of the Trophic State Indices indicate a mesotrophic level for the fluvial and transition zones, and an oligotrophic one for the lacustrine zone.
Descrição
Palavras-chave
limnologia, reservatório de Itaipu, qualidade da água, eutrofização, Brasil, limnology, Itaipu reservoir, water quality, eutrophication, Brazil
Como citar
Brazilian Journal of Biology. Instituto Internacional de Ecologia, v. 71, n. 4, p. 889-902, 2011.