SIMULAÇÃO DE VAZÃO APLICADA AO RESERVATÓRIO DA UHE FURNAS UTILIZANDO MODELO SWAT

Abstract

The hydrological model Soil and Water Assessment Tool (SWAT) is an important tool in the management of water resources, and can contribute to the estimation of streamflow to hydroelectric reservoirs. The objective of this study was to simulate the flow in the drainage area of the Furnas reservoir, located in the Rio Grande basin (MG). The series of meteorological and hydrological data included in the study corresponded to the period from 01/01/1998 to 12/31/2013. In the development of the model the following steps were adopted: (1) parameterization of the input data; (2) configuration of the model; (3) warm up and simulation; (4) sensitivity analysis; (5) calibration, validation and analysis of results. Calibration, validation and uncertainty analysis were performed using the Sequential Uncertainty Fitting (SUFI-2) algorithm through the Uncertainty Calibration Program (SWAT-CUP). The calibration and validation adjustment was measured by applying the P-Factor (percentage of the measured data bracketed by the 95PPU), the R-Factor (mean uncertainty band thickness) and the Nash and Sutcliffe (NSE) objective function. The P-factor values corresponded to 0.94 and 0.69 for calibration and validation, respectively. The NSE values were 0.86 for the calibration and 0.64 for the validation. The results obtained show a reasonable precision in relation to the literature, being within acceptable intervals, characterizing the model as adequate to estimate reservoir flows, considering the uncertainties of prediction. The construction of models from the SWAT allows the definition of best practices of management of water resources and of hydroelectric reservoirs.