Regional Landslide Inventory Mapping of Bashilo River Watershed, Ethiopia

Abstract

This study tentatively identified large bedrock landslide features across the Bashilo River, a tributary of the upper Blue Nile River of Ethiopia, using a geospatial mapping approach. The study aims to highlight the utilization of low-cost mapping techniques that might be applicable across large tracts of land (between 1000 and 500,000 km2). Topographic maps with 40 m contours were draped onto 30-m-spatial-resolution hillshade digital elevation models generated from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which were utilized to produce stitched hillshade topographic maps to allow the delineation of possible bedrock landslide features. The landslide identification process was aided by employing anomalous topographic protocols, including: divergent contours, isolated topographic benches, crenulated contours, and disturbed drainage patterns as key indicators of likely landslide related features. The mapping exercise identified several hundred landslide features, including some landslide complexes believed to be seismically induced, composite bedrock landslides, rotational slumps, earth flows, and translational block slides generally >500 m in length. This first-pass regional landslide inventory was based on moderate-resolution data and limited resources. The resulting maps are intended to serve as a general guide for regional hazard assessment, realizing that more detailed site-specific studies should be undertaken where mapped landslide features might pose a hazard to the placement of critical infrastructure, such as highways, railroads, pipelines, electrical transmission corridors, and structures.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

ASTER DEM; GIS; Hillshade Map; Landslide Inventory; Topography; Geographic Information Systems; Hazards; Induced Seismicity; Mapping; Rivers; Surveying; Advanced Spaceborne Thermal Emission And Reflection Radiometer; Digital Elevation Model; Electrical Transmission; Landslide Identification; Moderate Resolution; Site Specific Study; Bedrock; Contour Map; Blue Nile Basin; Ethiopia; Nile Basin

Geographic Coverage

Ethiopia

International Standard Serial Number (ISSN)

1078-7275

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Geological Society of America (GSA), All rights reserved.

Publication Date

01 May 2017

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