Abstract
To mitigate many impacts, several types of fishway have been developed until now. Among them, pool-and-weir-fishway are the most popular type in Japan, and the number of cases would be over 10, 000. The feature of the pool-and-weir-fishway has two just different flow patterns inside the pool; Plunging Flow and Streaming Flow. Although these flow patterns are fundamental factors whether fish succeed in accessing to the upstream or not, it was not made clear how to decide the parameters such as the pool length, pool depth and weir top pattern. In this study, these important parameters which influence these flow patterns were selected, and several patterns of experiments using an actual scale model were done changing parameters in various value in order to develop the way of designing the pool-and-weir-fishway. Furthermore, fish behaviors were observed in these flow patterns, and the features were grasped. This result could be good information to consider the series of the relation; the design of fishway, flow pattern and fish behavior.
