ABSTRACT
The formation and failure of landslide dam are common geomorphic process in the mountainous area all over the world. Landslide dams are also common in Japan because of widespread unstable slopes and narrow valleys exist in conjunction with frequent hydrologic, volcanic and seismic landslide triggering events. Historical documents and topography have revealed the formation of many landslide dams, some of which broke and caused major damage in Japan. The 2004 Chuetsu earthquake resulted in many landslide dams particularly in the Imo River basin. In 2005, typhoon 14 caused a large landslide dam near the Mimi-kawa river. Recently, eleven landslide dams were formed in Iwate and Miyagi prefecture due to landslides triggered by Iwate-Miyagi Inland Earthquake on 14th June 2008.
