Modelagem do regime térmico e caracterização do estado trófico de um reservatório tropical de abastecimento público

Abstract

The public water supply sources located in an urban area has come under heavy pressure from the real estate industry that sometimes does not spare the surroundings of springs forward the expansion of urban sprawl. Studies of these environments considering the physical system watershed are important to understanding the changes in the process of urbanization. In this context, this study aimed to provide a systemic view of the reservoir of São Pedro, Juiz de Fora / MG, based on evaluation of their thermal behavior through modeling, assessing its trophic state. We used the IPH-ECO model to simulate the surface temperature of the water on the basis of climatological and boundary conditions (flow rates in and out of the reservoir). The modeling was July 2010 to June 2011, where the parameters water temperature and dissolved oxygen were monitored. The total phosphorus tests were conducted to characterize the degree of eutrophication of the reservoir by calculating the trophic state index (IET). The results showed a low fertilization of the reservoir, with a predominance of oligotrophic environment according to the classification modified by Carlson Toledo. The simulation of the temperature of the water proved so efficient with over 90% representation. Temperatures behaved satisfactorily in the process of modeling, considering the flow of the tributaries. The simulations of water temperature on average by three points selected in the model output, were around 21.95 ° C and the observed temperatures, again on average by three points, were around 22, 21 ° C. Therefore, the representativeness of the model is efficient for the shell of São Pedro. The contribution of the tributaries was very important for the hydrodynamic simulations, as the variation of flow limits or regulates the temperature of the reservoir.