Influence of the Amazon Hydrological Regime on Eutrophication Indicators of a Hydroelectric Power Plant Reservoir

Abstract

Dam constructions in the Amazon have increased exponentially in the last decades, causing several environmental impacts and serious anthropogenic impacts in certain hydroelectric power plant reservoirs in the region have been identified. The assessment of the trophic status of these reservoirs is of interest to indicate man-made changes in the environment, but must take into account the hydrological cycle of the area. This can be relevant for environmental management actions, aiding in the identification of the ecological status of water bodies. In this context, physico-chemical parameters and eutrophication indicators were determined in a hydroelectric power plant reservoir in the Brazilian Amazon to assess trophic variations during the regional hydrological regime phases on the reservoir, namely dry, filling, full and emptying stages. The local hydrological regimes were shown to significantly influence TSS and turbidity, as well as NH, NO, PO, with higher values consistently observed during the filling stage of the reservoir. In addition, differences among the sampling stations regarding land use, population and anthropogenic activities were reflected in the PO values during the different hydrological phases.

Use of Geostatistical Models in the Space-Temporal Evaluation of Water Quality of an Amazonian Hydroelectric Reservoir

“…One justification for the less acidic condition in the mentioned regions, may be related to the reduced buffer capacity of some water bodies. Water bodies with low pH values typically maintain the presence of bicarbonate and carbonate compounds (Freire et al (2017); Piratoba et al (2017).…”