Abstract
A series of small hydropower dams have been constructed along gorge sections of river in Japan. It is important to study hydraulic characteristics of flood flow associated with hydropower dams which will be usable for the future flood control management. At first, we show the effect of the gate operation of small hydropower dam on flood propagation speed and discharge hydrographs from observed results and unsteady 1D flow analysis which was developed so as to consider the effect of the gate operation. Secondary, storage functions of a gorge with a series of small hydropower dams are evaluated on the basis of the results of unsteady 1D flow analysis before and after the construction of a series of small hydropower dams.
