Land Degradation Identification to Rehabilitate Upper Citarum Sub Watershed for Increasing Water Supply

Abstract

Land degradation in Upper Citarum gives problem not only for erosion and sedimentation in downstream, but also for decreases the infiltration due to higher surface runoff. The surface runoff from upper Citarum contributed to the flooding downstream, such as Bandung city and West Bandung District. The degraded areas could be determined through analysis of land vulnerability to erosion. The aim of this study is to identify areas vulnerable to erosion and to design a rehabilitation plan to reduce erosion and increase infiltration. It is expected that by doing the land rehabilitation, the surface runoff is decreased and the groundwater is increased. The land vulnerability is identified by overlaying land cover, land system and precipitation. The result shows that more than 50% of the total areas of Upper Citarum are vulnerable to erosion, 26% are very vulnerable and the rest are moderate to not vulnerable. The recommended activities for land rehabilitation in the vulnerable and very vulnerable areas are determined according to their functions: Forest and non-forest. In the non-forest function, the suggested activities are infiltration well, ponds, and planting forest trees; while in the forest function, especially in the protected forest, enrichment planting completed with water trap.