Earthquake-Induced Landslide Susceptibility Analysis :The Effect of DEM Resolution

Abstract

This paper study the effect of the Digital Elevation Model (DEM) data parameters ( type, source, and resolution) on a slope unit and landslide susceptibility analysis using Geographic Information System (GIS). The Landslide susceptibility analysis and slope unit delineation is done using six DEM data from three different sources (Bige Map, SRTM, and Wietu) at varying resolutions and pixel sizes. The Frequency Ratio Method is then used to analyze Ghana’s susceptibility to seismic landslides whiles; a pseudo-static critical slip method (Factor of safety method) is used to check the accuracy and also indicate the specific slopes to fail at specific seismic loading. The research aimed to achieve the goal since the method allowed for the attainment of an optimum slope unit and landslide map for each resolution of data regardless of the source. The procedure permitted and informed a decision making on the best DEM DATA and resolution for slope unit and Landslide analysis. The result showcases a DEM Resolution of 18 and 30 m and pixel 30m*30m size to be the best DEM to be used for landslide susceptibility mapping. The results further prove Bige Map and STRM DEM to give a more precise effect than weitu.