We surveyed damage to 146 buildings caused by the mudflows in the Izusan area, Atami City in 2021. As a result, wooden houses were almost washed away at a mud depth of more than 2 m, while RC buildings remained without significant structural damage. However, damage to wooden houses was greatly reduced in cases where there were obstacles such as RC buildings upstream, or where the houses were built on mixed structure with embankment, RC, S-structure foundations, or columns (pilotis).
