治水専用穴あきダムの洪水調節能力改善手法に関する研究

抄録

We propose a new type of 'dry dam' to make the most of storage capacity for flood control. Flood control dam without slide gate in spillway, known as 'dry dam', has been reviewed, planned and built in some sites. However, conventional dry dams can not adequately use the storage capacity for flood control. The new dry dam has some slide gates in a spillway which can be opened and closed automatically depending on hydraulic pressure (we call this gate 'pressure gate') in addition to a constantly open gate. All the gates are set at a river bed level. For each pressure gate, a critical water level to open and close a gate automatically is determined in each condition. Since an outflow rate increases even in lower water level using the 'pressure gates', the proposed dam could control flood adequately.

The effects of a new 'dry dam' on flood disaster management were investigated using numerical simulations. In this study, 'pressure gates' were applied as measures against excessive floods. As a result of this study, it is made clear that the new type of dry dam with pressure gates is extremely effective as a countermeasure against flood disasters.