Characterization of the Trend of Urbanization and Associated Natural Hazard Assessment and Analysis: Landslide and Earthquake Problems Along Hill Slope Areas in the Case of A.A City, Ethiopia
No Thumbnail Available
Date
2012-06-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Every year, in most urban areas, millions of people lost their lives due to natural hazards. The deadliest natural hazards in urban regions have been landslides, earthquakes and floods. In geologically unique regions where plates diverge, converge or sub duct, hazard intensity increased and huge losses resulted. In previous years, with similar repeated events (earthquakes, floods and landslides) hundreds of residents of Addis Ababa were inflicted to deaths and properties damaged. Notably, Addis Ababa is geologically dictated by the activities of the Afar plume magmatic rifting and the African magmatic up-wells. In two separate parts, this paper aims to identify and evaluate landslide and earthquake hazard prone areas and generate hazard risk maps. Yeka, Gullele, Kolfe Keraniyo, and Nefas Silk Lafto are sub-cities of Addis Ababa selected for this research work. While considered the population and land mass proportion, the selected areas encompass 34% and 46% respectively. Most of them have more or less dissected mountain upland morphology characterized by highly to moderately weathered volcanic lava products (basaltic and rhyolitic rocks; mostly cenezoic in age) associated with tectono-siesmic controlled structures (faults and dykes) potential to develop natural hazards. Current research evidences indicates that, on the rugged up-land hilly regions of Yeka, Gulele, Kolfe Keraniyo and some parts of Nefas Silk Lafto area; affected by the urban sprawls have been significantly marked as vulnerable areas to landslides and earthquake hazards. More often, significant portion of the south western zones where abundant condominiums constructed, i.e. Jemmo, Nefas Silk Lafto sub-city fall under high to moderate landslides and seismic vulnerability values.
Description
Keywords
Natural Hazards, Afar Plume, Magmatic Processes, Magmatic Up-Wells, Tectono-Seismic, Addis Ababa, Vulnerability, Risk