Estimating soil loss for sustainable land management planning at the Gelana sub-watershed, northern highlands of Ethiopia

摘要

The study was conducted with the objective of estimating the rate of soil loss using the Revised Universal Soil Loss Equation model for sustainable land management planning at the Gelana sub-watershed in northern highlands of Ethiopia. The geographical information system data layers, including factors for rainfall erosivity, soil erodibility, slope length and steepness, cover management, and conservation practice, were calculated to determine their effects on mean annual soil loss. The results indicated that the mean rate of soil loss from the Gelana sub-watershed was 24.3 t h~(-1) y~(-1); this is very low compared to the results of previous studies in different parts of Ethiopia. This might be attributed to area closure, and soil and water conservation measures implemented in the study area by the Ethiopian government in the last two decades. Results also showed that soil with erosion severity classes of high, very high, severe and very severe jointly accounted for 84% of the total soil loss of the entire Gelana sub-watershed, but covered only 22% of the total area. This highlights the need for implementation of soil conservation measures in these areas.