河床波の変形過程に関する研究(2)-洪水時における河床波の変動予測-

Abstract

The response of sand waves due to the time change of flow condition extending toboth the lower and upper regime was measured in a flume test varying flume inclination witha constant flow discharge. As a general tendency, it was found that in the lower regime theresponse seems to be slow and it appeared a remarcable time lag. On the other hand, inthe upper regime or transition, the response seems to be so quick that the bed form nearlycoincides with that for the steady state.Some hydrological and hydraulic data of several principal rivers in Japan were arrangedto estimate the bed configuration during floods, by means of a numerical simulation model.In some cases, the bed configuration is estimated to be dunes and the wave length and/orheight will differ considerably from those for equilibrium state.