Abstract
An estimation method of flood discharge hydrograph is developed that couples a 2-D unsteady flow model considering the effect of vegetation toppling and a 2-D model for bed elevation change due to bed load transport. The method is applied to a flush flood from the Haizuka dam in the Jouge River where vegetation became submerged with deformation in large areas. Measurements of water level hydrographs at several points, the discharge with ADCP at a weir and bed elevation change at a point were carried out during the flood. It is shown that the estimated discharge hydrograph gives reasonable agreement with the measured result and that the reliable data of bed elevation is crucial to accurate estimation of discharge hydrograph in a steep slope river.
