Water erosion is one of the main worries linked to tropical soil management, surface runoff being responsible for sediment transportation and bedding particles. The objective of this study was to adopt a semi-empirical hydrological model to surface runoff and peak discharge, applying the Modified Universal Soil Loss Equation (MUSLE) to a small watershed occupied by eucalyptus plantations and native forest, in the Coastal Table Land region, Aracruz, in the State of Espírito Santo, Brazil. Medium clayey texture Yellow Argisol (PA1), moderately rocky Yellow Argisol (PA8), and Haplic Plinthosol (FX) are the main soil classes. Hydrological data were monitored from 1997 to 2004. Models for surface runoff and peak discharge were adjusted, obtaining adequate estimates which can be used for hydrological simulation. The MUSLE model showed itself to be appropriate for soil losse prediction in the small watershed, the "a" and "b" coefficients recommended as being equal to 14.96 and 0.59, respectively, with a topographical factor equal to 1.28.
modeling; surface runoff; peak discharge; soil losses
