The aim of the present study was to calibrate and to validate the C factor of Universal Soil Loss Equation and the coefficients of the Modified Universal Soil Loss Equation for land covers of native ‘Caatinga’, thinned ‘Caatinga’ and grass (after deforestation and burning) in Brazilian semiarid region. Data were collected in the period 2009-2012. To evaluate the model performance, Nash-Sutcliffe statistical coefficient was determined, as well as the Willmott index (id) and confidence index (c). For determination of the C factor, data from erosion plots of a 20 m² were analysed, employing 50% for calibration and the other half for validation. For calibration and validation of the coefficients "a" and "b" of MUSLE, data obtained from watersheds (1.15 to 2.8 ha) were used. The largest value of C was recorded for native ‘Caatinga’ area (0.0167), followed by grass with 0.0084 and the lowest value of C (0.0067) was determined for the thinned ‘Caatinga’. The results showed that the adjusted values of the C factor and the coefficients "a" and "b" of the MUSLE were appropriate and recommended according to the statistical analysis, and it can be used to simulate similar ungauged watersheds.
soil loss; erosion; caatinga
