Estimated sediment exports and erosion in Central Citarum watershed

In addition to the problem of water availability and quality, the Citratum watershed is also experiencing problems with soil erosion and sedimentation. Climate change and land use cover are the leading causes of this. Therefore, monitoring water conditions and soil erosion is prioritized in the central Citarum watershed covering an area of 227,020 hectares. The purpose of this study was to determine soil erosion and the spatial distribution of sediment exports. The InVEST SDR method was used to calculate sediment exports and soil erosion. The results showed that the total sediment export of the Central Citarum watershed was 4.61 x million tons/year or an average of 20.31 tons/ha/year. Significant distributions occur in several sub-watersheds, including Cilawang, Cihalaya, Cipada, Citarum 58, and Cimurah, each contributing 36.56%, 14.83%, 13.70%, 4.73%, and 4.53 %. Meanwhile, total soil erosion is 23.16 million tons/year or an average of 102 tons/ha/year, with the most extensive distribution in the Cilawang sub-watershed, 35.12%. High sediment discharge occurs in areas with steep slopes, high rainfall, and dry land agriculture. Furthermore, efforts to reduce sediment exports to the Cirata and Jatiluhur reservoirs should focus on these five sub-watersheds.