| Project/Area Number |
07458024
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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 | 一般 |
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| Research Field |
自然地理学
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| Research Institution | Rissho University |
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Principal Investigator |
ARAI Tadashi Rissho University, Faculty of Letters, Professor, 文学部, 教授 (10062811)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Masanori Rissho University, Junior College, Professor, 短期大学部, 教授 (00174631)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥8,000,000 (Direct Cost: ¥8,000,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1995: ¥5,100,000 (Direct Cost: ¥5,100,000)
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| Keywords | river / stream network / discharge / stream velocity / stream depth / water temperature / travel time of water / Geographic Information System / 水系 / アナログモデル |
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| Research Abstract |
A GIS software for the model analysis of stream discharge, temperature and water quality has been developed and tested. The model is based on the assumption that mean velocity and mean depth may have specified values for each stream order. Investigations on velocity and depth were carried at about 130 stations in mountain streams near Tokyo. Mean velocity was deduced from amount of discharge, mean depth and mean width. It has been concluded that these parameters increase with the stream order and the mean value of each parameter is taken into the model analysis. The model covers 3^<rd> to 6^<th> order of streams, because permanent flow is not found in 2^<nd> order flow in general case.
Conjunction of segments and length of each segment have been analyzed by the GIS software, after then, data are transferred to Excel or Lotus for the calculation. Analysis on travel time of water by normalized form reveals that spectrum of the time shows concentrated shape in basins with large basin shape coefficient. Flat distributions are obtained in narrow and long basins. Distribution of stream temperature has been estimated by simple heat balance equation and weighted mean of the discharge volume. It has been concluded that about 60% of the tested cases are successful ; these are basins with many branches. Dilution of BOD is calculated introducing the self-purification and mixing with clear water from branches. It may be said that the model is also useful for water quality analysis.
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