Analysis of Erosion Hazard Levels using USLE Method in the Bati-Bati Sub-Watershed, Indonesia

The Bati-Bati Sub-Watershed is one of the critical watersheds that is susceptible to soil erosion. Soil erosion poses a significant threat to environmental stability, particularly in tropical regions. This study aims to analyze the level of erosion hazard and provide recommendations for forest and land rehabilitation to minimize the impacts of erosion. The USLE (Universal Soil Loss Equation) method was used to estimate erosion hazard levels in this research. The factors considered in this method include land cover type, slope class, rainfall, soil depth, and soil type. The study was conducted in the upstream and midstream areas of the Bati-Bati Sub-Watershed, which is part of the Maluka Watershed in Bati-Bati District. Thirteen land units were identified, with three main land cover types: plantation (10,186.6 ha), shrubland (7,367.4 ha), and open land (665.1 ha). The slope conditions are categorized into three classes: flat (14,744.9 ha), gentle (2,044.8 ha), and moderately steep (1,419.4 ha). The identified soil types include the Red Podzolic – Lateritic Complex and Organosol Gley Humus. Erosion hazard levels in the study area are distributed as follows: Level I–Low (7,606.7 ha), Level IV–Very Severe (5,369.8 ha), Level III–Severe (2,652.6 ha), and Level II–Moderate (2,579.9 ha). The recommended forest and land rehabilitation (FLR) strategies are grouped into three approaches: maintaining the existing plantation land cover and rehabilitating it with high-quality, site-adapted species; converting shrubland into Indonesian plantation forest models with appropriate species selection based on site suitability; and converting open land into agroforestry planting systems. Keywords: Agroforestry, Erosion Hazard Level, Forest and Land Rehabilitation, USLE method, Watershed