Avaliação da influência do fósforo e do nitrogênio no processo de eutrofização de grandes reservatórios estudo de caso: Usina Hidrelétrica Foz do Areia

Abstract

The objective of this study is to assess the influence of the nutrients phosphorus and nitrogen in the eutrophication process in the reservoir of the Foz do Areia Hydroelecttric Power Plant. The main impacts associated with eutrophication are restrictions in the use of the reservoir by the local community, and potential toxicity of cyanobacteria present in the process. This evaluation was done with a set of water quality Computer Models. First, the contribution of the main tributaries was evaluated with the FLUX program. Second, with results from this analysis and other information related to the vertical profile of water quality parameters obtained both experimentally and with the PROFILE program, the degree of eutrophication in the current situation was assessed and simulations of scenarios were carried out with constrained loads with the BATHTUB program. The results showed that the reservoir is in an eutrophic state, and that phosphorus is the limiting nutrient. Results were considered satisfactory, since there was good agreement between observed and modeled values. Also shown was the importance of the loading effect of the Iguaçu river on the Foz do Areia Reservoir, since it accounts for 86% of the phosphorus loads to the reservoir.