Hydro-sedimentologic models are useful in the environmental analysis of unmonitored watersheds. However, the models must be calibrated and validated for accurate predictions. The objective of this study was to calibrate MUSLE for the conditions of the Piripipau river basin (Brazil), using hydrologic and sedimentologic data from 1999 to 2005, and to validate the calibrated model with another data set (1998, 2006-2009). MUSLE's a coefficient was calibrated fitting observed and calculated sediment yield values of individual events, using observed hydrologic data (Q and q p). In the validation stage of the calibrated model, only observed rain gauge data and previously obtained CN, K, L, S, C, and P values of the watershed were used. Results indicate that the calibrated MUSLE fit better to total annual sediment yields (R² = 0.68 and E = 0.61) than monthly Y values (R² = 0.44 and E = 0.43). Since coefficient a was directly related to the annual precipitation volume, it can be used to improve MUSLE predictions.
calibration; validation; model; MUSLE; sediment yield
