EROSION DANGER LEVEL AND DEGRADED LAND MAPPING AT UPPER CIMANUK SUB-WATERSHED AREA AND THE IMPLICATION ON THE RIPARIAN RESTORATION

• Main Author: AGAVETRA A. (NIM : 11513050), ANDREAS
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21056
• Institution: Institut Teknologi Bandung

The environmental challenge, such as erosion and degraded land at the Upper Cimanuk Watershed Area, Garut Regency, is relatively high. The land-use change from forests to agriculture and housing areas contributes to the environmental problems at the specified sub-watershed area, including the river bank area. The distribution of erosion and degraded land at the specified area needs to be mapped for the future considerations of rehabilitation actions. The purpose of this research is to determine the danger level of the erosion, as determined using the Universal Soil Loss Equation (USLE) method with the geographic information system technologies. The danger level of erosion could be determined by overlaying the danger level of erosion map with the soil depth. Land degradation is determined spatially by overlaying the danger level of erosion map with the slope map, the land coverage map, and region management map. The analysis results show that the total erosion at the Upper Cimanuk sub-Watershed Area on 2015 was 3.338.790 tons. The average erosion in one hectare was 46,7 tons in one year. Generally, the danger level of erosion at the sub-watershed area of Upper Cimanuk was categorised as medium level, with the coverage area of 20,723.95 ha. The land degradation at the sub-watershed area of Upper Cimanuk could be classified as four classes, which is potentially degradation (2,773.49 ha), slightly degradation (47,366.46 ha), critical (20,905.94 ha), and highly degradation (227.29 ha). These results indicate that the Upper Cimanuk Sub-Watershed Area needs an intensive land rehabilitation so that it may minimising the land degradation level. The Cimanuk River Waterbank Area also needs a riparian ecosystem rehabilitation so that the river edge can be stabilised and minimising erosion. The intensive water bank rehabilitation effort needs to be prioritised for several districts, such as Banjarwangi District, Cikajang District, Cilawu District, Bayongbong District, and Cisurupan District.