抄録
A filed study and dynamic flood simulation on the Onga River heavy rainfall disaster in July 18-21, 2003 were conducted. Firstly, the flood process in the Iizuka-city area, which suffered the greatest damage in the Onga basin, was examined based on field study. Secondly, the flood simulation model was applied to the Iizuka-city area. The water movement in the urban area including the Onga River, main branch rivers was simulated simultaneously and the computed results compared with the flood process examined in the field study. Finally, the effect of the river improvements on the flood damage was examined through the numerical simulation. It shows that the model is a useful tool for examining the effects of the improvement work of a main river to inundation flows from tributary rivers.
