Impacts of Stone Bunds on Soil Loss and Surface Runoff: A Case Study from Gumara Maksegnit Watershed, Northern Ethiopia

Ethiopia is highly affected by land degradation and one of the key problems is soil erosion. It is mainly caused by the rapid population increase, deforestation, low vegetation cover and unbalanced livestock and crop production. As about 85% of the Ethiopian population is dependent upon agricultural production for their livelihood and source of food, it is essential to prevent or reduce further degradation. In the Northern Highlands of Ethiopia stone bunds are widely used as a soil and water conservation (SWC) measure. Stone bunds are small embankments of stones along the contour line, and influence the translation processes of surface runoff. In June 2015 a field experiment in the Gumara Maksegnit Watershed was carried out to investigate the impact of stone bunds on surface runoff and soil erosion using 4 m wide by 20 m long bounded plots monitoring surface runoff and sediment yield with and without stone bunds (Figure 1). The average slope of the plots was about 8%. The novel design of the plots (with stone bunds) allowed the monitoring of runoff along the contour (stone bund) as well as the bund overflow (Klik et al., 2015). The sideflow and overflow were separately collected and routed via a multi-slot-divider to different storage ponds (Figure 2). Representative samples were taken in weekly intervals for sediment concentration assessment. Precipitation was measured in daily intervals next to the study site.