In this study, I investigated characteristics of the damages induced by the heavy rain event of July 2018 in the Fukuoka Prefecture. It is located on the margins of the damaged area, and the numbers of damaged houses and deaths are lower than in other prefectures. Field survey results of four areas as reported in newspapers are mentioned.
In the Nakamuta of the town of Chikuzen, floodwater from the collapse of a dam bank on Nakajima pond increased flood damage of an elementary school on the terrace. In the Kitano-machi of the city of Kurume, the sufficient increased of the ground level of residential areas in the abandoned river channel led to reduced flood damage. In Kurume's Higashiaigawa, the pumping station's insufficient drainage capacity increased flood damage in the residential area, which used to be paddy fields. In Kurume's Jojima-machi, gate closure and insufficient pumping station drainage capacity increased flood damage of houses on the natural levee.
Thus it is clear that human activities that improve convenience and safety in Fukuoka Prefecture contributed to both increases and decreases in flood damage.