2001 Fiscal Year Final Research Report Summary
Comparative study on discontinuous nature of sediment transfers and changes of watershed management in river systems
| Project/Area Number |
10460060
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
林学
|
|---|
| Research Institution | University of Tsukuba |
|---|
Principal Investigator |
MAITA Hideji Univ. of Tsukuba, Inst. Of Agr. And For. Engin., Associate Professor, 農林工学系, 助教授 (50015864)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Osamu Miyazaki Univ., Fac. Of Agr., Associate Professor, 農学部, 助教授 (20178966)
MARUTANI Tomomi Shinshu Univ., Fac. Of-Agr., Professor, 農学部, 教授 (40112320)
KUROKI Mikio Hokkaido Univ., Graduate School of Engin., Associate Professor, 大学院・工学研究科, 助教授 (50002001)
MIYAZAKI Toshitaka Shinshu Univ., Fac. Of Agr., Associate Professor, 農学部, 助教授 (50021077)
|
|---|
| Project Period (FY) |
1998 – 2001
|
| Keywords | river system / sediment transport / discontinuous nature / stored sediment / stream order / stable channel / drainage basin |
|---|
| Research Abstract |
We conducted the drainage net analysis to examine the Horton's laws in Japanese basins. As a result, it is suggested that channel classification based on the stream order is effective to compare the characteristics of sediment transport between rivers in a basin level because the classification could represent regularities of channel form and the regional characteristics regarding sediment transport. We also analyzed sediment distributions along the river course in objective basins using the theory of stable channel by Kuroki. As a result, it is suggested that the variation from stable channel forms could represent the characteristics of sediment transport in rivers. Furthermore We examined the adjustment of unstable sediment stored in a mountainous bedrock channel of the upper Hitotsuse River, Kyushu, the bed-material transport estimated from channel morphodynamics of the Sorachi River, Hokkaido, the geomorphological properties and the time series movement of sediment yield in*the upper area of the Tenryu River, central Japan, and the sediment budget and sediment yield due to shallow landslides in the upper River Oi, central Japan. As a result, it is suggested that sediment storage in channels is most important to understand discontinuous nature of sediment transfers, and also the distribution of stored sediment in a drainage system and its changes by flood events are important to understand the dynamics of sediment transport in a basin level. Furthermore it is important to identify whether a channel is in supply limited condition or in transport limited condition because the imbalance between the stream power and sediment availability causes sediment storage.
|
