MUDANÇA DO USO DA TERRA E OS SEUS EFEITOS NOS PROCESSOS HIDROSSEDIMENTOLÓGICOS EM UMA BACIA RURAL

Abstract

Changes in land use often leverage the erosion causing water loss, soil, nutrient and organic matter, which is why we evaluated the change of land use and its effects on hydro sedimentological processes in Rio das Pedras basin, using SWAT software (Soil and Water Assessment Tool). Two scenarios were simulated. At first, the use of the current ground. In the second scenario, the current use has been replaced by native forest. The two simulated scenarios were compared analyzing flow and sediment yield and runoff. A database with the hydrological data required for proper application of the model in the basin was created. The model was calibrated in relation to the average monthly flow observed the pluviometric station ETA - Guarapuava in a period of 5 years (2004-2008) and then validated with the 5-year period (2009-2013). However, before calibrating the model made up the parameter sensitivity analysis in relation to the flow observed in the basin, using SWAT CUP software. After model calibration results Nash Index & Sutcliffe changed (COE), the percentage trend (BIAS), and the coefficient of determination (R²) were, respectively, 0.69, 0.5 and 0.7 indicating good fit between the monthly average flow of the Rio das Pedras basin simulated by SWAT model to the observed data. The study showed the influence of land use on hydrological variables. Thus, there was an average increase of 53.2% in the runoff, 12 times more on average sediment yield and the average flow there was a 14.9% increase when comparing scenario 1 to scenario 2.