Indícios de degradação ambiental em um reservatório oligotrófico (Reservatório De Serra Azul, Mg Brasil): avaliação limnológica, morfometria, batimetria e modelagem hidrodinâmica

Abstract

The morphometry of a reservoir consists of measuring physical parameters which define its shape and structure. In turn the morphometric parameters, affect almost all the physico-chemical and biological characteristics of a particular body of water, notably the heat-exchange relationship with the atmosphere. This work aimed at the creation of a new bathymetric chart of the main compartments inside the reservoir, with the calculation of primary and secondary parameters, as well as studying the horizontal distribution of limnological variables. The study was conducted in the reservoir supply Serra Azul, located in the metropolitan region of Belo Horizonte / MG, belonging to the COMPANHIA DE SANEAMENTO DE MINAS GERAIS COPASA MG. The bathymetric survey also includes the specific hidroacustics survey, the consolidation of a base map with submeter accuracy. The new bathymetric chart data showed little contrast with the literature. The area, volume and maximum depth were found respectively 9.11 km2, 8.16 x 107m3, and 47.3 m. There was a divergence of data found in literature, which can be attributed to siltation and methodological differences. The limnological profile of the reservoir showed a clear stratification, the epilimnion may be set up to 8m, the metalímnio up to 18m and from depth, the hypolimnion. Through the result of limnological variables and calculating the Trophic State Index (TSI), the reservoir was evaluated as oligotrophic, although it has some clear mesotrophic regions where the arm enters its main tributary. Thus, it is concluded that there were changes in the morphology of this reservoir since the last study in 2004 that could affect water quality and compromise its existence as a water supply reservoir.