Application of the Soil and Water Assessment Tool (SWAT) for sediment transport simulation at a headwater watershed in Minas Gerais State, Brazil

Abstract

The SWAT (Soil and Water Assessment Tool) model was used to simulate stream flow and suspended sediment concentration at the Lavrinha Creek Watersheds outlet, which is situated in the Mantiqueira Range region (Figure 1). This model requires some maps, such as Digital Elevation Model, land-use map and soil map. Temporal series associated to climatic variables, stream flow and suspended sediment concentration were obtained from an existing hydrological monitoring that has been conducted at or near the LCWs outlet since January of 2006. Eight months (January 2006 August 2006) were chosen as warm-up period of the SWAT model, while two years (September 2006 August 2008) were considered for the model calibration and two years (September 2008 August 2010) for the model validation. A statistical index known as Nash-Sutcliffe (COE) was employed to evaluate the model performance. Stream flow simulations with SWAT model on a daily basis resulted in COE values of 0.809 and 0.793 for calibration and validation periods, respectively; whereas, when simulating sediment concentration, the model resulted in COE values of 0.683 and 0.745 for calibration and validation periods, respectively. The SWAT model was considered adequate to simulate stream flow and suspended sediment concentration in the LCW, thus constituting in an important tool for water resources management in the Mantiqueira Range region.