Reactivation of mass movements in Dessie graben, the example of an active landslide area in the Ethiopian Highlands
Abstrakt
Dessie town is located in a tectonic depression along the western rift margin with a young, high energy relief. Study area is known for numerous landslides in the past.
These landslides are of different types, from shallow soil creeping to huge deep-seated landslides with appreciable consequences. Landslides endanger the quickly growing regional centre of Dessie and its infrastructure.
Four typical recent landslides have been selected and studied in detail using both remote sensing and field observations from 2013. The described reactivation and new landslide events have been caused by a combination of natural influences and anthropogenic activities.
Since seasonal rainfall is the main external triggering factor, precipitation data from Dessie weather station were analysed. The degree of negative human impact on slope instability was also discussed.
Endangered zones and the actual risk in the studied localities were identified, and adequate measures were proposed.