| Project/Area Number |
06452370
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Kyushu University |
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Principal Investigator |
MORI Ken Kyushu University, Faculty of Agriculture, Asistant Professor, 農学部, 助手 (50117272)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAMATSU Kazuaki Kyushu University, Faculty of Agriculture, Asistant Professor, 農学部, 助手 (10199094)
SHIKASHO Shiomi Kyushu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80038265)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1995: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1994: ¥5,500,000 (Direct Cost: ¥5,500,000)
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| Keywords | Thermal Stratification / Wind Mixing / Thermal Convective Flow / Wind Induced Flow / Dissolved Oxygen / Numerical Simulation |
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| Research Abstract |
Response of water temperature and dissolved oxygen vertical structures caused by disturbances added to the water surface, which were concerned with water quality and pollution control in shallow standing water areas, were studied. Disturbances are thermal and mechanical, which are the daily cycle of solar heating and cooling and the mixing and circulation due to wind stress.
Wind induced wedge shaped internal layr, which was developed at the windward in the water area and governed vertical mass transfer from lower to upper layr through the density interface, was investigated. When one dimensional wind induced mixing in the vertical direction was remarkable, the wedge shaped layr scale depended on an overall Richardson number, the magnitude of density in the wedge varies exponentially with time and the expansion and contraction rate of the wedge was prescribed by entrainmentrate through the density interface.
The dissolved oxygen (DO) daily cycle behaviors due to two disturbances was investigeated from field observation. It was founded that the vertical DO profile was sensitively responsed to thermal stratification and thermal mixing layr growth and was governed both reaeration at the surface and wind induced mixing.
Using field data on the water temperature profiles with time to disturbances, variations of vertical thermal eddy diffusivity profiles were founded by means of estimating fromone dimensional thermal diffusion equation in the vertical direction.
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