2010 Volume 47 Issue 1 Pages 1-7
Focusing on the most frequent angle of landslide slope, in this study we examined the engineering features of Tertiary formations along the Japan Sea in the eastern part of Shimane prefecture, based on 50-m DEM (Digital Elevation Model) topographical analysis. Our main conclusions are summarized as follows: (1) In the study area, the distribution and angles of slopes composed of stratum in the Iwami and Izumo groups can be affected by the direction of the slope. However, the most frequent angle of the slopes is not related to the slope direction. (2) The most frequent angle of landslide slopes is very similar to that of natural slope. (3) The most frequent angle of landslide slopes tends to decrease with an increase in stratum order. (4) For the stratum of the Iwami groups, the landslide slopes were distributed more often in the areas in which small slope angles were more prevalent. The most frequent angle of the landslide slope showed a particular value that was dependent on the kind of stratum. Therefore, the most frequent angle of the landslide slope can be a useful index for estimating the strength parameter of a landslide's slip surface.
