2012 Volume 18 Pages 245-250
In Ikarashi river, a risk of levee break was high at Niigata-Fukushima Heavy Rainfall Disaster in july 2011 because of occurrence of excessive flood. In order to comprehend fluid forces acting to channel, we conducted full 2-d analysis given the hydro of this excessive floods at channel has cross-section before the disaster. In this study, we discussed estimating indexes to predict disaster points due to flood flows. At a result of flow velocity and friction velocity, time integration of friction velocity has a close relationship of disaster points. Though current river channel designing method consider only velocity, the designing method should import the concept of time integrated friction velocity.
