Abstract:
Soil erosion is one of the major agricultural problems in the highlands of Ethiopia.
Identification of erosion areas on a regional scale can be very useful for appropriate soil
and water conservation measures and can help reduce land degradation. The aims of this
study were to assess soil erosion risk areas and to estimate annual soil loss rates of Menz
Mama Midir District using Geographic Information System (GIS) and Remote Sensing
(RS). In this study, annual soil loss rates are estimated using the Revised Universal Soil
Loss Equation (RUSLE) Model that has been used all over the world. Rainfall data, soil
data, and satellite image and Digital Elevation Model data were used as input data sets
to generate RUSLE factor values. Five principal factors were used to calculate soil loss
per year, such as rainfall erosivity (R), soil erodibility (K), slope length and slope
steepness (LS), land use/cover factor (C) and Conservation practice or erosion control
practice factor (P). Based on the analysis, the model final result shows that the current
annual soil loss of the study area ranges from 0 to 23,790.1ton/ha/year with the mean
annual value of 32.2 ton/ha/year from 65,101 hectare of land. These values were
categorized into four priority classes depending on the calculated soil erosion amount to
provide site specific conservation interventions. According to the study result, areas
which are classified as severe erosion class covers an area of 18,759ha which is about
28.89% of the total study area , high erosion risk class covers an area of 8447ha
(13.01%), moderate erosion risk class covers an area of 5,809ha (8.94%) and the
remaining 31,928ha (49.16%) are under low erosion risk classes. A majority of the high
erosion risk sites are on the banks of rivers and on the steep slope land of the study area.
This is due mainly to the high steep slopes along the river banks and the practice of
agricultural activities in this area. As a result, the areas that have high erosion risk
should be conserved and requires effective soil conservation measures.
