AM06-17-004 浮き石状態と沈み石状態の発生要因の相違(河川・湖沼・沿岸域の環境流体(1),一般講演)

概要

論文の詳細を見る
The ayu, Plecoglossus altivelis, spawns at the rapid in the lower reach of the rivers, because the velocity is high and also the bed condition is "soft bed". The soft bed condition is defined by fishermen as that the bed materials move if someone walks on the spawning bed. Fishermen make their efforts to keep soft bed condition during the spawning season. However, it is quite difficult to keep soft bed condition, because they do not know how to make soft bed condition in detail. In this study, the soft bed condition is investigated quantitatively by the field survey. It was found that the soft bed condition is satisfied if the weight of the removed bed material by one step is larger than 0.1Kg when someone walks on the river bed. Velocity measurements both in the water and under the bed in the flume were conducted. It was found that the soft bed condition is similar to the critical condition of sediment movement and also that the thickness of the mixing layer between the fixed bed material and moving one increase when the sift bed condition is satisfied.
日本流体力学会の論文
2006-09-05