抄録
In 2004, Mizuyama proposed the shutter sabo dam, which is a sabo dam with a shutter that can be opened under control. Such a dam has the advantages of both closed and open sabo dams. Recently, shutter sabo dams have been constructed on some rivers. In this study, we simulated a shutter sabo dam in the Ashiarai-dani basin using the KANAKO simulator equipped with a graphical user interface. We compared the effectiveness of the shutter sabo dam according to differences in when the shutter was closed. We also compared situations with and without a movable riverbed. Comparing the sediment discharge downstream from the sabo dam and the riverbed deformation upstream from the sabo dam, earlier closing of the shutter was more effective at sediment control. However, when there is a movable riverbed, earlier closing causes more riverbed degradation downstream from the sabo dam. Therefore, to operate shutter sabo dams properly, it is necessary to obtain detailed information on the water-discharge rates, water levels, sediment-transport rates, and riverbed material.
