Slope Management Planning for the Mitigation of Landslide Disaster in Urban Areas

Abstract

Japan is susceptible to slope failures and landslides. This paper will demonstrate how municipal governments can manage landslides with the use of inspection records and spatial data. Specifically, the study applies a multivariate analysis method, quantification theory type 2, to statistically evaluate the risk of slope failures caused by geomorphological factors. The scores from these analytical results reflect the risk of the slopes sampled in the analysis. We also analyze rainfall factors in order to determine the critical rainfall line and evaluate the critical line of the linear type conventionally used in disaster forecasting. By applying these methods, we identify the areas prone to landslides using GIS. Further, we developed a database system capable of combining spatial data with existing data on potential landslides. Two features of the system enable its application to all municipalities and prefectures throughout Japan: all local governments can make use of the inspection results, and all have access to various spatial data established under the ′e-government′ policy. This paper explains how to use rainfall data, existing inventory data on steep slopes, and records of past landslides for the management of landslides. The results of these analyses will specify and predict areas prone to collapse for warning and evacuation procedures.