1998 Fiscal Year Final Research Report Summary
Bed form and bed load variation of each grain size due to discharge change in mountain rivers with sand gravel mixture
| Project/Area Number |
09650568
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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 | Ehime University |
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Principal Investigator |
SUZUKI Koichi Ehime Univ.Civil & Environmental Eng., Dr Eng., Professor, 工学部, 教授 (70026285)
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| Co-Investigator(Kenkyū-buntansha) |
FUJITA Masaharu Kyoto Univ.Agriculture, Dr Eng., Associate Professor, 農学部, 助教授 (60181369)
MICHIUE Masanori Tottori Univ.Civil Eng., Dr Eng., Professor, 工学部, 教授 (10027245)
KADOTA Akihiro Ehime Univ.Civil & Environmental Eng., Dr Eng., Research Associate, 工学部, 助手 (80294784)
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| Project Period (FY) |
1997 – 1998
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| Keywords | mountain river / sand-gravel mixture / bed form / bed load equation / stair-like bed / bed load fluctuation |
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| Research Abstract |
Step-pool morphology and sediment discharge of each grain size in mountain rivers with sand-gravel bed are disussed by surveying a mountain river bed and carring out indoor experiments. The main results obtained in this study are as follows :
1) Sediment discharge in mountain rivers usually fluctuates with time due to the formation and destruction of gravel concentration formed discretely in the longitudinal flow direction which results in stair-like or transverse limb bed.
2) An equation for average bed lood for each grain size in a sand-gravel mixture is proposed by modifying the tractive force and critical tractive force on each grain size in a bed load equation for a uniform sand bed.
3) The step-pool structure in mountain rivers is changed with the combination and division of the steps, but it is not completely destroyed by the floods.
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