Author(s): Tatsufumi Miyazaki; Shoji Fukuoka
Linked Author(s): Shoji Fukuoka
Keywords: Driftwoods; Flood flow; Levee breach; Inundation; Numerical computation
Abstract: Successive large floods exceeding the designed discharge occurred in the Kagetsu River in July 3 and 14, 2012. The floods caused serious damages such as levee breaches and flood inundations in densely residential area. In this paper, we analyzed both flood behavior in the river channel and inundation area by numerical analyses of quasi-three dimensional flows and two-dimensional bed variations. Causes of levee breaches were investigated by field survey and numerical computation results of velocity distributions and bed variations during the floods. Numerical simulation showed that the river-crossing structure (Yuuta Bridge) caused severe overbank flows by the driftwood accumulations and large inundation over dense housing areas.
Year: 2015