Simulation of the impact of land use change on surface run-off in Karst Leang Lonrong Sub-Watershed

Wahyullah Wahyullah (Graduate Study Program in Forest Management Science, Department of Forest Management, Faculty of Forestry and Environment, IPB University, IPBDarmaga Campus, Bogor, 16680, Indonesia)
Hendrayanto Hendrayanto (Graduate Study Program in Forest Management Science, Department of Forest Management, Faculty of Forestry and Environment, IPB University, IPBDarmaga Campus, Bogor, 16680, Indonesia)
Yuli Suharnoto (Department of Civil and Environmental Engineering, Faculty of Agricultural Technology, IPB University, IPBDarmaga Campus, Bogor, 16680, Indonesia)

Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management)
Vol 13 No 2 (2023): Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (JPSL)

Estimation of surface run-off in karst watersheds has not been widely carried out and the estimation method is generally developed for non-karst watersheds. This study aims to analyze the accuracy of estimation of river discharge at the outlet of the Karst Biringere Sub-watershed using the modified Soil Conservation Service Curve Number (SCS-CN) method and analyzed the impact of land use change on river discharge at the outlet of the Karst Biringere Sub-watershed. Modification of the SCS-CN method in estimating direct flow at the outlet of the Beringere Sub-watershed is influenced by the similarity of rainfall and direct flow fluctuation of river discharge. The modified SCS-CN method provides satisfactory direct flow estimation when rainfall with observed direct flow of river discharge forms a linear relationship with a strong correlation. Changes in land use with reduced forest cover into mining areas result in increased run-off and reduced storage, the larger the forest land becomes mining areas, the greater the increase in run-off and reduction in storage. Reclamation of the former mining area to be a forest reduces run-off and increases water storage.