Integrating MUSLE andsediment trap efficiency for oxbow lake service-life estimation, Krueng Keureuto Watershed

Abstract

Annual flooding in the Krueng Keureuto Watershed causes significant losses to the surrounding community. One flood-control measure is the use of an oxbowlake, which is cyclical and lake that stores excess water when river discharge increases, provides clean water, and supports irrigation. However, the lake’s mainproblem is sedimentation, which can reduce its capacity and shorten its service life. Therefore, this study analyse the sedimentation rate and estimate the lake’s service life. The sedimentation analysis was conducted using the modified universal soil loss equation (MUSLE) method. The study used rainfall data from 2011 and 2023, a topographic map generated from digital elevation model (DEM) data, soil-type and land-use data, and lake storage capacity.The analysis shows that the oxbow lakecatchment area is dominated by inceptisols, while primary dryland forest is the largest land-use category, covering 276.12 km². The slope length and steepness (LS) factor value was 2.33. With an annual sedimentation rate of 53.47 m³∙y⁻¹, the oxbow lake has an operational lifespan of 3.9 years, at which point the dead storage capacity is filled with sediment. These results can support management in determining maintenance strategies, dredging plans, and other measures to sustain thelake’s function for flood control and downstream water supply.