2020 Volume 26 Pages 663-668
The Kagetsu River in the Chikugo River water system suffered heavy damage due to flooding caused by heavy rain in northern Kyushu in July 2012. In response to the damage caused by the flood, a special emergency project for countermeasures against severe river disasters was adopted, and river channel excavation, embankment construction, and renovation of crossing structures were implemented. The Kagetsu River is a rapid river that forms a fan from a mountainous area through a narrow mountainous area. In flood control measures for such rapid rivers, it is important to respond to "high flow velocity" and "sediment flowing in from mountainous areas". In this report, we report the points to keep in mind when designing a river channel in the project, and the effects and issues of the project that were confirmed byflooding thereafter.
