Land Use Optimization for Mitigation of Sedimentation in Lisu Watershed, South Sulawesi
Abstract
Lisu watershed in South Sulawesi Province is included in the second priority watershed with the carrying capacity recovery. This study aimed to assess the SWAT model performance in predictingflow discharge and sediment yield, to determine the best land management on Lisu watershed.There are several stages in running SWAT model, including watershed delineation, HRU definition, climate data input, write SWAT input files, run SWAT model, calibration and validation, and hydrological parameters simulation.The land management scenario used in this study is a regional spatial plan scenario (RTRW) to simulate hydrological condition of Lisu watershed by the regional planning of Barru Regency government. The regional spatial plan scenario (RTRW) is also the basis for modifying other scenarios (optimization of forest functions, rehabilitation of critical land, and soil and water conservation techniques with vegetative methods) to optimize land management in Lisu Watershed.The study indicates that SWAT model had a good performance to simulate flow discharge with R2 and NSE values in calibration process of 0.72 and 0.5 respectively. In general, the model still showed smaller result than the observational data.The results showed that scenarios could reduce surface runoff, water yield, lateral flow and increase groundwater. The best conditions are generated by the critical land rehabilitation scenario, with a river regime coefficient value of 124.87, and the highest decrease in sediment yield (88.07 ton/ha)
