2000 Fiscal Year Final Research Report Summary
Field experiments on the functions and capabilities of a coastal drain system as a measurement for beach erosion control
| Project/Area Number |
10555179
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
水工水理学
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| Research Institution | Kagoshima Univarsity |
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Principal Investigator |
SATO Michio Kagoshima university, Faculty of Engineering, Professor, 工学部, 教授 (40005450)
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| Co-Investigator(Kenkyū-buntansha) |
NISHI Ryuichiro Kagoshima university, Faculty of Engineering, Assoc.Professor, 工学部, 助教授 (30189253)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Coast / Coastal Drain / Beach erosion / Measures for erosion / BMS / dewatering / littoral drift / Field experiment |
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| Research Abstract |
We conducted field experiments of a Coastal Drain System with prototype scale three times during the period between the fiscal year of 1998 and that of 2000. The objectives of the experiments were to investigate the effectiveness and capabilities of a Coastal Drain System as measures for beach erosion control, and, if it is effective, how it works.
The sites of the experiments were Kashiwara beach and Iso beach in Kagoshima Prefecture. Vesterby reported several meters shoreline advance after two weeks of the installation. This motivated us to plan the field experiments. Although, our drainage were larger compared with the one of his, we could not see the accumulation of expected large amount of sediments. This may partly due to the way to drain groundwater. Conventional method drains groundwater into a sump by gravity. In our experiments, pumps were joined to pipes and drained directly with suction continuously. We adopted this method as it was expected to enable the drain discharge become larger, which is a merit for short-term experiment.
The measurements of the compaction of beach surface showed that the part of near pipes seemed to be compacted and become tighten due to the suction. This compaction effect seemed to be one of important factors to resist an erosive wave action. This may be considered to be a new point of view on the function of a coastal drain. The data that was obtained through these field experiments will have importance as the verification data in the development of a numerical model. Also, from the practical point of view, the experiences of these proto type experiments are considered to become hints on the installation of the system. The issues we should examine about the fundamental physical processes that are related to the functions of a coastal drain system have become clearer through these field experiments.
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