Slope Gradation Maps as a Useful Tool for Detecting Landform Features
Izumi KAMIYA and Hiroshi P. SATO
Slope gradation maps, which are easily driven from DEM, and which directly show slope of land surfaces without vegetational interference, are used to detect landform features. We found two geological problems using slope gradation maps. One concerns the area of serpentinite distribution. Though interpretation of slope gradation maps shows very clear serpentinite-like characteristics in the Kamuikotan metamorphic belt, it does not in the Sangun metamorphic belt. An area of gabbro in the Sangun metamorphic belt looks just a serpentinite area on a slope gradation map. The other problem concerns lineament: a clear lineament was found on a slope gradation map. Hypothesizing the existence of some geological structure along the lineament, we found much indirect evidence supporting the hypothesis. In conclusion, slope gradation maps are useful in geology and geomorphology for finding unknown problems.
3. Examples of detecting landform features by slope gradation maps
3.1 Distribution of serpentinite in the Sangun metamorphic belt.
3.2 Lineament around the Mashu Caldera