2006 Fiscal Year Final Research Report Summary
Evaluation technique for erosion rate of cohesive sediment and its application to the geomorphological
| Project/Area Number |
17560463
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
水工水理学
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| Research Institution | Waseda University |
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Principal Investigator |
SEKINE Masato Faculty of Science and Engineering, Professor, 理工学術院, 教授 (60187854)
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| Project Period (FY) |
2005 – 2006
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| Keywords | cohesive sediment / erosion rate / eroded landforms / movable apparatus of erosion test |
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| Research Abstract |
Erosion process of cohesive sediment was investigated experimentally in this study. Fundamental studies had been already conducted in the experimental flume to evaluate the erosion rate of uniform cohesive sediment. In this study, we developed a movable apparatus of erosion test, which was designed to conduct a field measurement of erosion rate of naturally deposited cohesive sediment. We also established the experimental techniques for such a measurement. Several series of measurements were conducted in large-scale open-air experimental flume in order to check the validity and utility of this apparatus. It was verified that the results had almost same order of accuracy as that by our standard test in laboratory. This is one of the main achievements of this study.
The effect of cohesiveness of sediment on the erosion process of bare-slope was also investigated here. This is the second part of this study. Experiments were conducted to investigate the geomorphological change in model bare slope, which was constituted by cohesive sediment, due to an artificial rainfall. Before doing that, the information about the experimental technique of erosion test of cohesive sediment by us was instructive. Clay content ratio is only the parameter to be changed in this series of experiments. It was seen that the main channel which formed on the slope grew narrower and deeper as the clay content ratio increased. Vertical erosion on the bed was found to be more dominant than the lateral bank erosion. It was also understood that the erosion process and the geometry of channel network in case of cohesive bare slope have different characteristics than those of cohesionless slope.
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Research Products
(12 results)
