Influence of Relative Water Depth on Riverbed Evolution and Flow Structure around Groines in Open-channel Flows

The groin changes from non-overflow condition to overflow condition in the actual river according to the flow discharge. In that case, it is thought that the riverbed and flow structure around the groin always changes. The flow characteristics and morphological responses around single groin has been clarified. In the present study, it aims to clarify the characteristic of the bed form and flow characteristics around six groines for changing relative water depth by the laboratory experiment under the condition to assume the Froude number to be 0.2. The bed form in the larger relative water depth has large scale of the scour. Accretion point in main flow region moved to groin region and downstream. The flow velocity of the main flow region become slower in the downstream.