Peranan Lahan Berbasis Agroforestri Terhadap Neraca Air Di Das Bialo, Sulawesi Selatan

Hydrological functions of watershed are potential environmental services which may be affected by human
activities in utilizing land. Hydrological modeling approach can be used to analyze the response of hydrological
functions to land utilization. In this study, Generic River Flow (GenRiver) model was used to analyze the
response of Bialo watershed (114 km2) to land conversion (one of land utilization indicators) that is situated in
Bantaeng and Bulukumba districts, South Sulawesi. There are four steps applied in this study: (1) model
parameterization, (2) model calibration and validation, (3) land covers changes scenarios development, and (4)
scenarios simulation. The first three steps represent current condition of Bialo watershed, whereas the last step
simulates some scenarios that might be happen in the future. Four different scenarios have been done in this
study: (1) Business As Usual (BAU), (2) converted 50% of agroforestry into shrub, (3) converted 100% of
agroforestry into shrub, and (4) converted 100% shrub into agroforestry. The result of the first three scenarios
shows that surface flow increases by 9% (scenario 1) and more than 25% (scenario 2 and 3), whereas base flow
decreases by 1.7%, 6.9% and 14.2% respectively. In contrast, scenario 4 can decrease surface flow and increase
base flow. These results show that the increasing area of agroforestry system in Bialo watershed can enhance
water balance of the watershed and GenRiver model can be used as a tool to support the analysis of
hydrological condition of watershed.