ATTEMPT TO RECREATE THE FISH BEHAVIOR IN SMALL SIZE RIVER AT THE EXPERIMENTAL CHANNEL

Abstract

 The object of this research is to find out a suitable model experimental condition in the model open channel to reproduce the real characteristics of behavior of fish in a natural river in where the flow usually is unstable.
 From observations and experiments, it becomes clear that in the model channel fish shows the characteristic moving near the wall of channel. But in the real channel in the field, fish does not show such behavior, because the shape of cross section of channel is not regular.
 If a spur dike is set in an open channel, bending flow occurs. Fish move upstream against this bending flow. And then, water course is formed on the bottom, the flow bends to the right and left more. Flow is more similar to the natural stream flow. As the result, fish move to upstream against to this bending flow.