Abstract
We analyzed the relationship between the distribution of unstable topographic features such as landslides and linear depressions, altitude, and the geology of the area in a 1: 200, 000 sheet map of Gifu using Geographic Information System (GIS). The analyses clarified that unstable topographic features are extensively developed in the areas of the Tetori Group and limestone belonging to the Mino terrane, while they are less developed in the Cretaceous granite. Although granitic rocks in Japan are considered to be one of the lithologies causing few deep-seated landslides, Neogene and Jurassic granites in the study area have more deep-seated landslide topographic features than average. The linear depressions extracted from the topographic maps are divided into two groups: features related in spatial distribution to landslide topographic features and features developed as precursors of future landslides. Thus both the linear depressions and the landslide topography are good indicators of slope instability. Most of the linear depressions seem to have been formed during the dissection stage of the low-relief erosion surface.
