Review of the occurrences and influencing factors of landslides in the highlands of Ethiopia: With implications for infrastructural development

  • K Woldearegay

Abstract

The hilly and mountainous terrains of the highlands of Ethiopia are frequently affected by rainfall-induced landslides of different types and sizes. The major types of landslides reported to have been triggered by heavy rainfalls include debris/earth slides, debris/earth flows and, and medium to large-scale rockslides. Though rockfalls are common in the Ethiopian highlands no association is made with rainfalls. Review of the previous studies revealed that landslide hazards have been causing: loss of human lives, failure of engineering structures, damage on agricultural lands and on the natural environment. Medium to large-scale rockslides were reported in areas underlain by Paleozoic glacial sediments and volcanic rocks. Evaluation of the relationship between landslides and various influencing factors show that the debris/earth slides/flows have prevailed in: (a) areas which are underlain by Paleozoic glacial sediments, shales, and basalt flows, (b) hillslopes characterized by slope angles in the range 15-45 degrees, (c) terrains represented by concave shapes with some on planar surfaces, (d) areas affected by active gully erosion/artificial excavations, and (e) places represented by sparse or no vegetation cover with deeper roots. With regard to the triggering mechanisms, most of the rainfall-induced landslides have taken place in the late periods of the rainy seasons (late August to early September) following heavy rainfalls indicating that process is related to raise in groundwater level coupled with a certain intensity of rainfall event. Ethiopia is currently involved in massive infrastructural development (including roads and railways), urban development and extensive natural resources management. In this whole socio-economic development, landslides and landslide-generated ground failures need to be given due attention in order to reduce losses from such hazards and create safe geo-environment.

Key words: Review, Landslides, Highlands, Ethiopia

Published
2013-02-11
Section
Articles

Journal Identifiers


eISSN: 2220-184X
print ISSN: 2073-073X