Geospatial-Interface Water Erosion Prediction Project (GeoWEPP) application for the planning of Bompon Watershed conservation-prioritized area, Magelang, Central Java, Indonesia

Bompon watershed is located in the Quaternary Volcano (Mt. Sumbing) and tertiary (Mt. Menoreh) transition zones. The implication is that the soil material is well developed with super thick characteristic and is sensitive to erosion. The existence of land processing interventions by the locals supports the increasingly high rate of erosion. The use of the GeoWEPP model facilitates the rapid calculation of erosion rates and evaluation of conservation applications. The aim of the study was to calculate the erosion rate and determine the priority areas with the GeoWEPP erosion model. The GeoWEPP application was chosen because of its ability to show the spatial distribution of erosion and sedimentation. Evaluation of prioritized areas is carried out with the erosion rate criteria of the model and the important value of the land. The results of the Bompon watershed erosion model show variations in erosion and sedimentation. High erosion is in hilly morphology (slope of > 25) with agricultural land annual crops (moor) and mixed gardens. High sedimentation is on the colluvial plains with moorland and rice fields land use. The existence of agricultural areas with cassava, corn and rice commodities has important value for villagers. Agriculture is the main livelihood of the community so that it has priority in handling conservation to maintain the productivity of the agricultural land. The assessment criteria for rate erosion and important value of the land produce priority sub-watershed that location covering 2 locations with an erosion rate of 441 tons/ha and 438.2 tons/ha.