Different calibration procedures for flows estimation using SWAT model. Issue 3 (2nd July 2020) - Moreira, Luana Lavagnoli
Abstract : This paper evaluates the calibration effectiveness for estimating monthly average flow using the SWAT model in a watershed located at Espírito Santo state in Brazil. Six methodologies were tested, which differ from each other by varying calibration parameters, size of historical series and number of sub-basins associated with the process. SWAT-CUP was used for the calibration tests and its effectiveness was analyzed by three objective functions: Percent bias (PBIAS), Nash-Sutcliffe efficiency (NSE), and Ratio of the Root Mean Square Error of measured data (RSR). Tests with long historical flow data (29 years long) did not generate satisfactory outputs. However, the best results were obtained while calibrating all parameters for all sub-basins with a data series of only 3 years long. From the results, we highlight the importance of a better description of the methodologies used in the calibration process, since different results can be obtained by the same input data.