GIS Based Soil Loss Estimation Using RUSLE Model: The Case of Jabi Tehinan Woreda, ANRS, Ethiopia

Abstract

Soil degradation in the form of soil erosion is a serious and continuous environmental problem in Jabi Tehinan Woreda. Uncontrolled land use, deforestation, over cultivation, overgrazing and exploitation of biomass for firewood, construction and other household uses due to increasing population ultimately lead to severe soil erosion. The impact of natural hazards like erosion can be minimized and ultimately controlled by disaster preparedness maps. Therefore, the overall objective of this paper is to quantify and map an estimated soil loss by examining different topographic and anthropogenic factors for the planning and implementations of sustainable soil conservation and management system in the study area. This study had integrated Geographic Information System (GIS), Remote Sensing (RS) and Multi-Criteria Evaluation (MCE) techniques to quantify and map erosion vulnerable areas using RUSLE model. Slope gradient, slope length, soil type, soil conservations techniques, cover management and rainfall variables were used as input model parameters/variables. The data had been collected and analyzed from different land sat imageries, SRTM data, topomaps and point interpolations of primary data. Finally, the aggregated effects of all parameters had been analyzed and soil loss from the area was calculated using RUSEL models. After analyzing all model parameters, areas in steeper slope with Lithosols, Eutric Nitosols, Orthic Luvisols, croplands, bare lands and river banks have been identified as the most erosion vulnerable areas. Quantitatively, an estimated annual soil loss in Jabi Tehinan Woreda ranges from nearly 0 in south and central parts of the area to 504.6 t/ha/yr in steeply sloping mountainous areas of the north and north-eastern parts of the catchments.