Abstract
A flow regime was examined experimentally in the Hybrid-type fishway (width B=0.8m, slope I=1/10) consisted of a recutangular notch (b=0.2m) at the center wall and a triangular type weir at the either wall (1: 7). Hydraulic characteristics in the pool of the fishway were understood by three-dimensional distribution and two-dimensional distribution of velocity in the case of both a pool-type flow and a stream-type flow. Especially, as regardsto the flow regime in the stream-type, at the center traverse section, the quasi-smooth flow which was occurred by linearly flow from the notch and the rotate flow to upstream direction at the down stream of the notch were formed.On the other hands, over flow on the triangular type weir formed the drop flow, the characteristics of this flow type was shown. There, if it was supposed that a value of the application critical velocity was 2m/s-3m/s, and the Froude's similarity was applied at 1/5 contraction scale, it was considered that the maximum discharge of the practical fish way would be 3.0m3/s in the case of PL/B=0.46 (PL=horizontal pool length) which formed the stream-type flow.
