  The forest plays an important role in a watershed hydrology, regulating the
transfer of water within the system. The forest role in maintaining watersheds
hydrological regime is still a controversial issue. Consequently, we use the
Soil and Water Assessment Tool (SWAT) model to simulate scenarios of land use
in a watershed. In one of these scenarios we identified, through GIS
techniques, Environmentally Sensitive Areas (ESAs) which have watershed been
degraded and we considered these areas protected by forest cover. This scenario
was then compared to current usage scenario regarding watershed sediment yield
and hydrological regime. The results showed a reduction in sediment yield of
54% among different scenarios, at the same time that the watershed water yield
was reduced by 19.3%.
