To the best of our knowledge, the assessment of meteorological disaster such as debris flow has not yet been examined with respect to long-term occurrence intervals. However, assessing the possibility and cycle of occurrence of debris flow that reaches habitat areas is important when considering future sediment disaster prevention. Heavy rainfall in August2014 induced numerous debris flows in Hiroshima, SW Japan. Our field survey results showed that multiple paleo debris flow deposits exist along the observed streams in Yagi-Midorii and Kabehigashi area. Radiocarbon dating using carbonised materials contained in paleo debris flow deposits ware used to infer the debris flow history. Our data revealed that in the Ueyamagawa/Yagi-Midorii area, large-scale debris flows have occurred at least four times: in the lst-2nd, 5th-6th, 7th-8th and 19th centuries AD. In the Kabesawa/Kabehigashi area, debris flow has occurred at least three times: in the 8th-9th, 16th-17th and 20th centuries AD.
展开▼
