GIS Based Analysis of Landslide Effecting Factors in the Pyeongchang Area

Most areas in Gangwon-do are mountainous regions where causes heavy damages due to landslides. It is important to analyze basic factors influencing the cause of landslides in order to prevent such landslides. For this study, a landslide occurring site is extracted from aerial images taken after the landslide caused by typhoon "Ewiniar" in Pyeongchang area 2006. Also, the overlay analysis with the topographic, forest, and soil maps in this area is performed using GIS based methods. In addition, the topographic, forest, and soil characteristics relating to the landslide factors are analyzed. As a result, large numbers of landslides occurred at a slope angle of 20°- 40°. In the case of the forest factors, there are close relationships between the artificial pine and larch forests and the frequency of landslides. The low forest density represents a weakness in landslides. In the case of the soil factors, a higher level in the surface soil with a type of sandy loam soil, a higher gravel content in subsoil, and a higher degree of acid rocks in soil parent materials cause higher frequencies in landslides