階段式魚道におけるプランジングフローおよびストリーミングフローの発生条件

抄録

Fishways are river constructions which facilitate migration of fish. The pool-and-weir fishway is typical type. There are three types of flow regimes in pool-and-weir fishways such as a plunging flow, streaming flow and intermixed flow of plunging and streaming flows. Onitsuka et al.(2005) found that the number of parameters of the plunging flow are four. However, it is quite difficult to conduct the systematically experiments. From the point of view of the engineering, it is necessary to predict the flow pattern roughly and easily with a few parameters. If effects of some parameters on the flow regime are small, such parameters may be neglected. In this study, order comparison of each parameter was conducted. As a result, the strength of effects of each four parameter on the flow regime is made clear. A new criterion formula, which can predict the flow regime in the pool-and-weir fishways with three parameters, was suggested.