Assessment of Landslide Risk in Ethiopia: Distributions, Causes, and Impacts

Abstract

The complex geological and geomorphological settings of Ethiopia, consisted of highland plateaus, escarpments, deeply dissected valleys, and flat lowlands, are results of multiple episodes of orogenesis, peneplanation, crustal up-doming, faulting, and emplacement of huge volumes of lava. The broad elevation contrast raging from about −125 m to 4550 m Above Mean Sea Level (AMSL) is an important factor in determining the climate regimes, vegetation types, and even populations’ lifestyles. In Ethiopia landslides, mostly manifested as rockfall, earth slide, debris, and mudflow, are among the major geohazard problems that immensely affects life, infrastructures, and the natural environment. They widely occur in the central, S-SW, and N-NW highland regions. This study discusses the distributions, causes, and impacts of landslides and presents a susceptibility zoning map produced applying the weighted overlay analysis method in the ArcGIS environment. For this purpose, key parameters (lithology, elevation, rainfall, slope angel, land use-land cover, and aspect) were selected and assigned weights by considering their contributions to slope failures. Correlations with inventory data have shown very good matching, where more than 90% of the observed data fall in areas categorized either as moderate, high, or very high susceptible zones, where appropriate risk assessments could be mandatory before approval of major projects.

Landslide vulnerability mapping using multi-criteria decision-making approaches: in Gacho Babba District, Gamo Highlands Southern Ethiopia

“…4f, soil types of the study area are reclassified into five categories (acrisols, nit sols, fluvisols, litosols, and calcic xerosols) and the majority of the area is occupied by Acrisols (73%). Acrisols are among soil types commonly found in highland areas characterized by low levels of organic matter and are highly prone to landslide hazards because of delayed infiltration [26]. Thus, possible to conclude that soil type is among the contributing factors for landslide hazard that has been and will also continue to be a causative factor for landslide hazard susceptibility in the study area.…”

“…Block B encompasses east and west Gojam and Gondar. Block C represents south and southwestern Ethiopia whereas; Block D constitutes the eastern part of the Main Ethiopian Rift [26].…”

Landslide Susceptibility Mapping Using GIS and Bivariate Statistical Models in Chemoga Watershed, Ethiopia

“…In Ethiopia landslides mostly manifest as rock fall, earth slide, debris and mudflow especially in the steep and hilly areas of the highlands greater than 1,500 m altitude [7,8]. According to Meten et al [9], from 1960 to 2010 about 388 people are reported dead, 24 injured, and a great deal of agricultural lands, houses, and infrastructures were affected.…”

GIS-Based Landslide Susceptibility Mapping Using Frequency Ratio and Shannon Entropy Models in Dejen District, Northwestern Ethiopia

“…In Ethiopia, landslides, mostly manifested as rock fall, earth slide, debris, and mudfow are among the major geohazards, especially in the steep and hilly areas of the highlands with greater than 1500 m altitude [7,8]. According to M. Meten et al [9], from 1960 to 2010, about 388 people are reported dead, 24 injured and a great deal of agricultural lands, houses, and infrastructures were afected.…”