Effect of the Substitution of Agricultural Uses by Forest on the Hydrological Processes in a Tropical Watershed. Analysis through Hydrological Simulation

Abstract

Forests play an important role in watershed hydrology, regulating the transfer of water within the system. Their role in maintaining the hydrological regime of watersheds is still a controversial issue. Due to the uncertainty, our first objective was to identify, through GIS techniques, “Environmentally Sensitive Areas” (ESAs) in the Pinhal watershed, subsequently, to simulate land use scenarios with the Soil and Water Assessment Tool model. In one of these scenarios, we considered these areas as protected by forest cover. This scenario we compared to the current scenario regarding watershed sediment yield and hydrological processes. The results showed a reduction in sediment yield of 54% between the two scenarios, whereas watershed water yield was reduced b y 19.3%.