Bodenerosion in Semien-Äthiopien

Abstract. The soil erosion map in hand is integrated in an interdisciplinary work with zoology and botany which deals with the problems of an Ethiopian National Park in the High Semien Mountains. Wide areas of the high plains between 3,200 and 4,000 metres above sea level formed by Trapp-Basalt are damaged by soil erosion. In order to take effective measures against the irreversible damage in this potential disaster area, the present Situation was mapped in a primary phase in the autumnof 1974:

1) The present forms of erosion were mapped.
2) Based on numerous profües, the structure of the soil was investigated and typified in an ideal profile. The thickness of the upper black horizon was measured by 500 different samples, evaluated and presented areawise.
3) On arable areas differentiation between 4 classes of damage was made: heavily to negligibly damaged areas.

The map established shows that soil erosion occurs principally on ploughed land. Tendencies to damage according to exposure, form and incline of the slope are clearly shown. An evolution of the forms of soil erosion can be derived. Possibilities for protective measures against soil erosion are available, but have not been used until today.