Influência operacional de um reservatório na dinâmica de nutrientes no processo de eutrofização – estudo de caso UHE Tucuruí

Abstract

The Amazon region contains a large water reserve, with rivers that present favorable behaviors for the installation of new dams. However, this change brings with it alterations in hydrological behavior, which leads to limnological changes, caused not only by the act of the water damming, but also by the increased population attracted to these areas in search of new opportunities. This leads to the generation of nutrients that are then released into the water body, mainly due to the precarious effluent treatment in these regions. In this context, the aim of this study was to calculate the Trophic State Index (TSI) at the Tucuruí HPP reservoir, through the aid of software packages and laboratory analyses of field data, analyzing the spatiotemporal behavior of the main nutrients responsible for this process in this area, using two models, namely Carlson‘s (1977) and Lamparelli ‗s (2004) models. The study also proposes a statistical analysis of the relationship between the behavior of the operational regime of the hydropower plant (HPP) with the situation of eutrophication of the reservoir, aiming to evaluate damming implications in the eutrophication process that occurs in the reservoir and its consequences. Eutrophication variability was observed both spatially and temporally, by the Lamparelli (2004) classification, where some points presented an oligotrophic classification during several years, indicating good water quality. However, through Carlson‘s methodology, most of the reservoir was classified as eutrophic, with lower water quality.