Does forest replacement increase water suply in watersheds? Analysis through hydrological simulation

TL;DR

This study uses hydrological simulation to evaluate how replacing degraded areas with forest cover affects water supply and sediment yield in watersheds, revealing significant reductions in sediment but also in water yield.

Contribution

It applies the SWAT model to compare land use scenarios, demonstrating the impact of forest restoration on watershed hydrology and sediment control.

Findings

Sediment yield reduced by 54% with forest replacement

Watershed water yield decreased by 19.3% after forest restoration

Simulation results support forest cover as a tool for sediment control

Abstract

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%.