抄録
Riverbed degradation occurs in many rivers in the world. It causes serious problems in river management. For example, the bedrock which had been covered with gravels is exposed due to the riverbed degradation, which destabilizes river structures, such as bank revetment works and groundsill works. In this study, hydraulic experiments were performed to determine sediment transport characteristics on bedrock channels partly covered with gravels. We obtained the following results. The bedload transport rate and the friction coefficient can be related with the coverage rate of gravels on the channel bed. A simple mathematical model describing sediment behavior on bedrock channels was proposed.