Author(s): Taisuke Ishigaki; Kazuhiko Hattori; Koji Shiono; Hiroaki Shimada
Linked Author(s): Taisuke Ishigaki
Keywords: Flood disaster; Doubly meandering compound channel flow; TELEMAC-2D
Abstract: In the last decade, extreme weather events have been observed all over the world and also in Japan. One of them is a heavy rainfall of which intensity is over 50mm/hr in Japan. And then, more than 100mm/hr rains are observed few times a year in the last decade. In such rainfalls, runoff discharge was increasing rapidly and getting over the conveyance of drainage system and river section, and the surrounding areas were flooded and damaged. These floods attacked alluvial plains and mountainous valleys. The focal point of this study is flood disaster in a stream valley. The stream valley means that a meandering stream runs in a valley. To verify the applicability of TELEMAC-2D, experiments was conducted in a case of doubly meandering compound channel flow. The model was applied to the flow and was verified the applicability with the experimental data. Using this model, the Asuwa river flood in 2004 was successfully simulated and it is found that the flood damage can be explained on the basis of velocity distributions of flooding flow over the flood plains.