Statistical analysis of landslide susceptibility at Yongin, Korea

The aim of this study is to evaluate the susceptibility of landslides at Yo ngin, Korea, using a geographic information system (GIS). Landslide locatio ns were identified in the Yongin area from interpretation of aerial photogr aphs, field surveys, and maps of the topography, soil type, timber cover, a nd geology. These data were collected and constructed into a spatial databa se using GIS. The factors that influence landslide occurrence, such as slop e, aspect, and curvature of topography, were calculated from the topographi c database. Texture, material, drainage, and effective soil thickness were extracted from the soil database, and type, age, diameter, and density of t imber were extracted from the forest database. Lithology was extracted from the geological database, and land use was classified from the Landsat TM s atellite image. Landslide susceptibility was analyzed using the landslide o ccurrence factors by probability and logistic regression methods. The resul ts of the analysis were verified using the landslide location data. The val idation results showed satisfactory agreement between the susceptibility ma p and the existing data on landslide location. The GIS was used to analyze the vast amount of data efficiently, and statistical programs were used to maintain specificity and accuracy. The results can be used to reduce associ ated hazards, and to plan land use and construction.