場の条件の設定手法が表層崩壊発生箇所の予測に及ぼす影響

抄録

In this study, we showed new data and proposed new method to analyze shallow rapid landslide susceptibility. We linked a simple hydrological model and the infinite slope stability model to calculate critical steady-state rainfall required to cause slope instability. The model was applied to a steep forested headwater of Hiroshima Seibu Mountains, western Japan. We measured soil thicknesses at 173 points in the catchment using a portable penetration test. We also measured stream flow rate and soil pore water pressures. If we used the data about soil thickness measurements and hydrological observations, the spatial distribution of critical steady-state rainfall were consistent with the spatial pattern of shallow landslides triggered by the heavy rainfall of June, 1999. However, if these data were not available, the spatial distribution of critical steady-state rainfall were not conjunction with the spatial pattern of landslides.