Abstract
The geomorphological features for the occurrence of landslide dams are examined in a case study of the 2004 Mid-Niigata Prefecture Earthquake based on digital elevation models(DEM)and the actual landslide distribution map. Found quantitatively shown that larger landslides along a narrower valley with a larger amount of river discharge have a tendency to induce landslide dams that cause river blockage. Accordingly, a new map showing the potential risk of landslide dams based on the overground-openness and the catchment area is proposed in this study. The combinational use of this map with the landslide risk map previously proposed by Hayashi et al.(2011) can be useful for the exact prediction of landslide dams that can be induced by a strong earthquake. In addition, the relationships between the accumulation height of the landslide mass and the local overground-openness in the original topography are examined for use in prediction of the height of a possible landslide dam.
