Forest trees on alluvial fan play major roles in the disaster prevention of the debris and flood flows, as in their environmental aspects. In order to retard the flows and protect houses on alluvial fans, we need knowledge of the interaction between the flows and forest trees. The purpose of the present study is to investigate the flow behavior and sediment deposition within the forest-tree area during the debris and flood flows. Two kinds of experiments were made; one examines the sediment transport rate within the model-tree area and the other the effect of model trees on sediment runoff and deposition. In the former experiments, sediment transport rate was measured on the. whole channel bed with the multiple rows of cylinders installed uniformly. It is found that the sediment transport rate can be expressed by effective shear stress. In the latter experiments, cylinders were installed in multiple rows on the downstream part of the whole channel bed. In the case of larger density of cylinder arrangement, sediment deposition occurs in the upstream reach of the model-tree area, while, in the case of smaller density, sediment deposition occurs in the downstream reach of the model-tree area. The runoff of sediment volume from the model-tree area decreases as the model-tree area becomes larger.
|出版ステータス||出版済み - 2003|
|イベント||3rd International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment - Davos, スイス|
継続期間: 9月 10 2003 → 9月 12 2003
|その他||3rd International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment|
|Period||9/10/03 → 9/12/03|
!!!All Science Journal Classification (ASJC) codes