Assessment of soil loss using RUSLE method in Mrica Reservoir catchment, Central Java, Indonesia

The Indonesian government has identified the Serayu Watershed as a priority area for restorationwithin the National Mid-Term Development Plan. One of the significant challenges in this region is the highlevel of soil erosion, which threatens the overall ecosystem. This study aims to estimate the amount of soilloss in the Mrica Catchment using the Revised Universal Soil Loss Equation (RUSLE) Method. Various datasources were utilized, including soil type, rainfall, land cover, Digital Elevation Model, and conservation data.Geographic Information System (GIS) techniques were employed to calculate the critical factors required bythe RUSLE Method, including soil erodibility (K), rainfall erosivity (Ri), slope length and steepness factor (LS),and cover management and conservation factor (CP). This research provides critical information for landmanagement in Mrica Catchment. These factors were used to estimate soil loss in the Mrica Catchment,revealing a range between 62,553 tons per year (t/y) and 21,323,311 t/y, with an average value of 443.90ton per hectare per year (t/ha/y). These results indicate high erosion potential based on the Classification of Erosion Hazard (HER). This study provides critical information for land management and offers suggestionsfor devising effective strategies to mitigate sedimentation impact in the Serayu Watershed. The highest soilloss values according to the RUSLE Method, both under the Environmental and Management Variable, areobserved in the same location, namely, in the north of Mrica Catchment. The findings emphasize the urgentneed for erosion control measures and sustainable land management practices in this priority restorationarea.