Abstract
Rivers possesses the function of storage and peak discharge attenuation of flood water. Author's recent studies have deepened basic understanding of these important characteristics of the flood flow. At the river confluence, downstream boundary conditions of a tributary change with time. The water flowing from the upstream and going against a stream is stored in the tributary.
Furthermore, at the river confluence, a water level changes with time and a reverse water surface slope occurs under the time change in the downstream boundary conditions. It is difficult to estimate accurate flow rate of the tributary in such hydraulic conditions. This study aims to estimate by new method discharge hydrograph and storage rate in the neighbourhood of the confluence of the Tone River and the Watarase River.
