Penggunaan Metode USLE dan MUSLE Terhadap Laju Erosi dan Sedimentasi DAS Tanggul Kabupaten Jember

Abstract

Recently five villages around the Tanggul Jember watershed are prone to flooding. Annually, the region is susceptible to flooding due to its inability to handle excessive water discharge caused by heavy rainfall and unfavorable watershed circumstances. The overflow produces sediment loads due to erosion and materials. To prevent this disaster, it is important to research the prediction of erosion and sedimentation rates in the Tanggul Watershed. Some of the methods are Universal Soil Loss Equation (USLE) and Modified Universal Soil Loss Equation (MUSLE). The primary data used is rainfall data for eleven years (2012-2022) at six rain stations, soil type maps from PU SDA JATIM, DEM data, and land cover maps. Rainfall data is used to obtain the erosivity factor, the Bols formula is used in the USLE method and the MUSLE method requires peak discharge using the Nakyasu hydrograph and runoff volume. Soil type data, DEM data, and land cover are processed using ArcGIS to obtain the required index values. Based on calculations for ten years, the average erosion rate for USLE was 461,791 tons/ha/year and for MUSLE it was 642,814 tons/ha/year. The USLE method was used to calculate the average annual sedimentation rate, which was found to be 9,046 tons per hectare per year, and the MUSLE method of 12,593 tons/ha/year. The analysis results were obtained using the USLE and MUSLE methods, the erosion rate ratio is 1:1.39. The difference between the two methods is the erosivity factor. The MUSLE method integrates numerous values and factors to precisely determine peak flow, surface runoff, and surface runoff factors.