Avaliação da aplicabilidade do modelo SWAT na bacia hidrográfica do rio Ibicuí

Abstract

One of the main challenges involved in hydrological modeling is the efficient calibration of model parameters. The objective of this study was to adjust a hydrological model with semiautomatic calibration for the Ibicuí watershed using the Soil and Water Assessment Tools (SWAT) model. The simulation was carried out considering the following input data in its processing: hydro-climatic variables (flow, precipitation), temperature, land use and land cover map (LULC), types of soil (TS) and the digital elevation model (DEM). The precipitation and flow data were obtained from the Agência Nacional de Águas e Saneamento Básico (ANA) and reference the period from 2011 to 2020, the temperature was obtained from Instituto Nacional de Meteorologia, the LULC map of 2018 was obtained from the Instituto Brasileiro de Geografia e Estatística (IBGE) and DEM was taken from NASA’s Shuttle Radar Topographic Mission (SRTM) at a spatial resolution of 90m. For parameter sensitivity analysis, calibration and model validation, the SWAT-CUP Software was used, which through the Sequential Uncertainty Fitting (SUFI2) algorithm, performs uncertainty tests for each simulated parameter. The series of observed flows from the ANA was divided into different periods for calibration and validation, and the SWAT model showed a satisfactory fit for estimating the flow at the BHRI, with a NashSutcliffe value (NSE)=0.87 and Pbias=- 14.1% for calibration and NSE=0.88 and Pbias=-22.2% for validation. Thus, although some limitations were found in the available input data, the obtained results showed a great potential for using the SWAT model to determine flows in the region of study, which could serve as support for future research, as well as backing for decision-making to water resource managers.