Abstract
In sediment disaster, not only crucial hazards but also relatively small scales of multiple hazards make evacuation behavior dangerous. In this study, the integrated sediment runoff model connecting a landslide model and water-sediment transport model was employed to the actual sediment disaster caused in Tanba city, Hyogo, Japan. The temporal and spatial variation of risk was estimated in 3 groups of multiple hazards (rainfall-related, landslide-related, and flood-related hazards). The occurring times of landslide-related and flood-related hazards were agreed with the disaster report. This method can also estimate the risks in advance using the virtual rainfalls. In this paper, the risks in 3 rainfalls which have different timing of rainfall peak were estimated. The results showed that the difficulty of evacuation was not equal because the progress process of each hazard group was different according to rainfall characteristics.
