MODELAGEM DE EROSÃO E APORTE DE SEDIMENTOS EM BACIA HIDROGRÁFICA COM O MODELO WaTEM/SEDEM

Abstract

This paper aimed to calibrate the WaTEM/SEDEM model and to simulate erosion, sediment deposition, and sediment yield at the outlet of the São Domingos stream watershed, in the municipality of Santa Cruz do Rio Pardo, in São Paulo state, as a result of the heavy rainfalls events considering land use conditions in 2018 and the alternative scenario of land use adequacy to the Brazilian Forest Laws (FL). We determined and mapped the factors of the Revised Universal Soil Loss Equation (RUSLE), which is the erosion component of the model. Using rainfall, discharge and sedimentometric data from real rain events, we calibrated and applied the WaTEM/SEDEM model to the land use conditions analyzed. There was a reduction in soil loss and sediment yield at the watershed outlet and an increase in sediment deposition in the watershed in FL scenario if compared to the base year 2018, due to the increase in forests, soil conservation techniques, sediment trap efficiency, and parcel connectivity, which promoted the reduction of the topographic factor. The results show the need for a joint analysis of physical environmental factors, watersheds’ hydrological and landscape structures, and land use in erosion studies.