Research on Accumulation Mechanism of Freshwater Red Tide in a Dam Reservoir
| Project/Area Number |
06680491
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SOMIYA Isao Kyoto University, Faculity of Engineering, Professor, 工学部, 教授 (60025947)
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| Co-Investigator(Kenkyū-buntansha) |
ONO Yoshirou Kyoto University, Faculity of Engineering, Instructor, 工学部, 講師 (50152541)
TSUNO Hiroshi Kyoto University, Faculity of Engineering, Co-Professor, 工学部, 助教授 (40026315)
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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 |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1995: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | fresh water red tide / Peridinium / dam reservoir / accumulation mechanism / head of lake / phototaxis / flow / 抑制対策 |
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| Research Abstract |
I.The diurnal change of distribution patterns and standing crop of Peridinium were observed at the head of Shourenji Dam Reservoir in autumn. There were three distribution patterns ; (a) accumulating at the surface in the day time ; (b) dispersing to lower layr and stream in the night ; (c) dispersing lower layr near the plunging point. The standing crop of Peridinium increased at similar rate of growth day by day. Since organisms were transported by the counter flow, The biomass periodically varied at 24 hours cycle in a day. These results show that the red tide develops and dissipates in the balance of growth, import and export.
II.Swimming velocity vectors of Peridinium were measured under various temperature and light intensity conditions. Analyzing obtained data sets, we constructed a mathematical model that predicted the vertical swimming velocity of Peridinium community. Furthermore, using the water tank and the mathematical model that assuming the head of a water reservoir, we examined the accumulation and dispersion processes of red tide. The mathematical model including the vertical swimming responses could simulate the diurnal change of biomass.
III.We developed the mathematical model that simulate the accumulation mechanism of freshwater red tide. It predicts the import and export using the fluid dynamics model, the vertical distribution using the vertical swimming model, and the growth using the ecological model. This model successfully simulated the temporal and spatial distribution of Peridinium at the head of Shourenji Dam Reservoir. These results suggested that accumulation mechanism of freshwater red tide could be treat in the term of engineering.
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Report
(3 results)
Research Products
(9 results)
