[MGI25-P04] Extraction of past shallow landslides by using Improved Minimum Eroded Value Method - An application on Houfu Area in Yamaguchi Prefecture western Japan -
Keywords:shallow landslide, DEM, GIS, Minimum Eroded Value, summit level
Minimum Eroded Value Method (Cooley, 2015) is used to evaluate eroded volume of a watershed by calculating difference between capping surface (summit level) and the original DEM. In the original method by Cooley (2015), capping surface is constructed by connecting a set of points located along the divide. This method is difficult to apply to volume calculation of small landslides, because the ridge lines are usually obscure for the small catchments. We selected the points with positive curvature value and used them to generate TIN surface as the capping surface. This method can visualize landslide scarps with different size by changing the grid size in the curvature calculation. The 2m grid will be probably most appropriate size for detection of shallow landslides induced by 2009 rainstorm in Houfu area.
Cooley, S.W., 2015, GIS4Geomorphology: http://www.gis4geomorphology.com (Accessed February, 2018)