Soil erosion prediction using GeoWEPP model in Cimanuk Hulu sub-watershed

Abstract

Abstract Runoff, soil erosion, and sedimentation can be used to assess the watershed condition. GeoWEPP is one of the erosions predictions models that can be used to predict those parameters and also can be used as a tool to arrange watershed management. Cimanuk Hulu sub-watershed is one of the important watersheds in West Java Province, Indonesia, as its function for water resources for Jatigede reservoir. The condition of this sub-watershed is in poor condition because of the high rate of sedimentation in water body. Therefore, we use the GeoWEPP model to assess runoff, erosion, and sedimentation in the Cimanuk Hulu sub-watershed. The model is also used to arrange the watershed management scenario. The input data are climate data, soil characteristics, land cover management, channel characteristics, digital elevation model, soil and land cover map. Land cover types were classified using Google Earth Engine (GEE) with SmileCART algorithm. Soil samples, land cover management, and channel characteristics were collected from the field survey. The result showed that runoff value in the existing condition is classified as a high class that affected higher soil erosion and sediment yield compared to tolerable soil loss in the Cimanuk Hulu sub-watershed. Simulation of watershed management showed that scenario 3 is the best in reducing the runoff, erosion, and sedimentation in the Cimanuk Hulu sub-watershed.