ABSTRACT
A regularly spaced DEM was created from 1:25,000scale digitized topographical maps at a spatial resolution of 25 m. Two thematic maps of slope and aspect were classified from raster of the DEM data. The geological setting of the study area is relatively uncomplicated, and the bedrock outcrops are mainly andesite, most of which is extremely weathered and susceptible to landsliding. The 1:50,000-scale map of geology was downloaded from an official website of Land and Water Bureau, Ministry of Land, Infrastructure and Transport (MLIT), Japan, and then used to construct the lithology database. For ease of analysis, rock types were categorized into 9 classes. A soil distribution map was also downloaded from the same website and digitized at a scale of 1:50,000. Land use/cover was extracted from the ortho-images dated February 29, 1999 and February 25, 2002, to update a land use map of the study area generated before 1984.
