1999 Fiscal Year Final Research Report Summary
Construction of the sediment transport model covering whole catchment area
| Project/Area Number |
10650498
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
MANO Akira faculty of engineering, graduate school, Tohoku University, professor, 大学院・工学研究科, 教授 (50111258)
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| Co-Investigator(Kenkyū-buntansha) |
NAGABAYASHI Hisao faculty of engineering, Nihon university, 工学部, 助教授 (70102431)
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| Project Period (FY) |
1998 – 1999
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| Keywords | sediment transport model / wash load / floods / material transport / sedimentation / 栄養塩類の輸送 |
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| Research Abstract |
Mano dealt with the Abukuma River and constructed channel network with 500m-grid size covering the whole catchment area. They have developed the system to compute the runoff on the network with the kinematic wave approximation and by inputting the distributed rainfall based on the AMeDas observation. They then have developed a sediment transport model on the same network by using the flow field obtained by the runoff analysis and by considering the physical processes of erosion, settling and convection. The model is shown to have high accuracy through the comparison with the observation.
Izumi executed field survey on the wash load carried by the flood of the Abukuma River in 1998 and has shown that spilled flood into the flood channel made significant deposition near the central edge like a natural bank and the grain size distribution became finer toward the other edge. He has developed the theory on the suspended load transport and shown that the observed distributions of sedimentations and grain size are explained by the theory.
Nagabayashi studied the transport of nitrogen, phosphorus and turbidity material in the Abukuma River. The characteristics of their concentration are investigated for floods and usual currents. During floods, turbidity has high correlation with the concentration of total nitrogen and total phosphorus. The ratios of the dissolved components to the total nitrogen and total phosphorus are shown to significantly change depending on the concentration of these total quantities. It suggests the ratios are effective to determine these loads.
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