Characteristics of Flood Damage in Futaba Area, Toride City of Ibaraki Prefecture, Caused by Heavy Rainfall Associated with Typhoon No.2 (Mawar) and Baiu-front in 2023

Abstract

From June 2 to 3, 2023, heavy rainfall exceeding 400 mm of accumulated precipitation was observed from Kochi to Kanagawa Prefectures due to Typhoon No.2 and Baiu-front. In the Kanto region, 286 mm of precipitation was observed in Toride City in southern Ibaraki Prefecture. Futaba Danchi in Toride City suffered internal flooding with a maximum flood depth of 1.2m due to overflowing water from surrounding waterways, resulting in 324 houses half destroyed and 240 houses flooded under the floor out of 1,120 houses. In the Futaba area, where housing construction began in 1966, the population and aging population are now rapidly declining. For this reason, evacuation support for persons requiring support for evacuation action, etc., is being reconsidered.