Flood control and irrigation system using tidal current generating device by 'UTSURO'

摘要

"Sea hollow (UTSURO)" is part of a water area surrounded and enclosed by a bank structure in a tide-level-changing water area. By using a tide generator by a "sea hollow (UTSURO)" which spreads a canal mouth that opens a "sea hollow (UTSURO)" water area via a canal toward a river's upstream part to open it in a tide-level-changing river-upstream water area, the functional extension of a rive is shortened, a river bed gradient is steepened, the flow rate and the tractive force of a river are increased, a river bed is deepened, a river section area is enlarged, and a drainage of inner basin and a flood discharge capacity are increased. At a downstream part, the size of "sea hollow (UTSURO)" A is increased, a tidal stream producing capacity is boosted, a tidal stream as large in quantity as a flood is produced, and a water stream section area is enlarged, thus contributing to a flood control effect and water way maintenance. In addition, in order to remove enormous amounts of sand and earth forced to flow to a river mouth and deposited on a river channel, another holes-rich "sea hollow (UTSURO)" B is installed to capture slurry by the action of high tide for precipitating and cleaning to thereby develop tidal flats and reclaimed lands, and, at a low tide, clean supernatant is collected into a channel to thereby produce tide. Furthermore, the installing of an outer block-enclosing bank (8) can prevent the outflow of slurry into an outer water area and further enhance their effects to maintain a canal. Additionally, in order to maintain the functions of the "sea hollow (UTSURO)" A, a canal length is increased to prevent a turbid water inflow.