プールタイプ魚道におけるオイカワの跳躍遡上と水理特性との関係

抄録

A pool-and-weir fishway was constructed beside of a large weir in the river, which is located at the northern part of Kyushu Island. In this fishway, all migrating fishes do not swim in the water flow running above the weir but are jumping in the air. Behaviors of jumping fishes whose name is Zakko Platypus are recorded by a digital video camera and three components of velocity in the first pool were measured with a 3-D electromagnetic current meter. It was found that almost fishes were jumping near the side-wall due to the velocity of the falling flow running above the weir near the side-wall is slower than that at the center of the channel. The initial speed of the migrating fishes is in proportion to the body length of migrating fishes.