Abstract
A habitat for the migratory fish, such as salmon and ayu, is separated after construction of a large drop in a river. This is because the fish cannot migrate over the large water difference. Recently, a construction method by making use of both a steep channel and pool has attracted a great deal of public attention, due to the migration is possible in this structure. In contrast, the hydraulic jump may occur in the pool when the river is flooded. The length of the hydraulic jump in open-channel flows with an abrupt rise is controlled by the Froude number and the ratio between the inlet flow depth and the height of the abrupt rise. On the other hand, the location of the toe of the hydraulic jump is not able to predict at present. If the location of toe and length of the hydraulic jump can be controlled, the cost of construction decreases. In this study, USBR-type III was constructed in the pool and the effects on the location of toe and length of the hydraulic jump is investigated with changing the inlet Froude number and inlet flow depth.
