Communication and Application of Engineering Geology for Community Based Disaster Preparedness

Abstract

Climate change has led to increasingly extreme weather events all over the world. In Japan, also the frequency of torrential rains has increased, and the number of rainfall-induced disasters occurrence annually continues to increase. Therefore, it is necessary for everyone to consider how to protect themselves from the rainfall-induced disasters beforehand. In Japan, mountainous areas account for about 70% of the land area, yet the population is concentrated in the 30% of flatlands. Consequently, dwellings and buildings in mountain villages are scattered. In mountainous area, local government-designated evacuation shelters are often distant. Evacuating to these shelters during heavy rain frequently requires traversing hazardous areas, making it an inappropriate action in many cases. Therefore, for living on mountain slopes, protecting oneself during heavy rain requires personally evacuation planning that consider the disaster risks around one's home and the surrounding roads. In Japan, since hazard information on mountain slopes is defined only for the immediate vicinity of residences, the hazard information is sometimes lacking for evacuation routes. This study conducted terrain analysis using a Digital Elevation Model (DEM) to explore the geotechnical support that can be provided to assist with evacuation planning in mountainous areas. It also examined, through field surveys and discussions within the study area, whether the terrain analysis results were useful for residents when formulating their evacuation plans.