Keywords:disaster prevention education, Debris flow disaster, Historical document
On September 6-7, 1898, a typhoon brought continuous torrential rain which caused floods and severe damage in the whole of Yamanashi Prefecture. In particular, a debris flow occurred at 1:30 a.m. on September 7 at the southern foot of Yatsugatake, leaving 55 people dead and 51 injured in Yato village in Oizumi-mura. The author investigated newspapers published at that time, and the "National Disaster Pictures" and "Storm Damage Survey Tables," both compiled in the Meiji era and archived in the Imperial Household Agency. He also inspected the disaster-stricken area in detail, including carrying out a survey using a drone. The historical data indicate that the debris flow branched off in three directions at the exit of the ravine of Miyagawa. One went in the southeast direction, which was continuing in the direction of the ravine. The other two flowed south and southwest, respectively. The debris flow to the south struck Yato village and inflicted serious damage. With 110 years having passed since the event, not only what was caused by the debris flow but also the disaster itself has disappeared from the memory of most local people. In this paper, the author also explores the possibility of raising the awareness of the local residents by reconstructing the image of the disaster from historical documents and using modern techniques, such as computer simulation of the debris flow.