2022 Fiscal Year Final Research Report
Development of an analysis method for flushing of river mouth gravel bar due to erosion
| Project/Area Number |
20K04711
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 22040:Hydroengineering-related
|
|---|
| Research Institution | Chuo University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2020-04-01 – 2023-03-31
|
| Keywords | 河口礫州 / 河口砂州 / 準三次元解析法 / 非平衡流砂運動 / 側岸崩落 / 自立高さ / サクション |
|---|
| Outline of Final Research Achievements |
Evaluation of riverbank erosion is important for flushing of river mouth gravel bars. Based on a non-hydrostatic quasi-3D flow model, a bed variation model that takes into account the flow three-dimensionality and the non-equilibrium motion of gravel particles was developed. And we developed a method to analyze the intermittent process of riverbank erosion caused by riverbank collapse by taking into account the effect of the suction. This method was applied to a field experiment on the Joganji River conducted in 2006, and the calculation results showed good agreement with observed data. Moreover, the effectiveness of the model was demonstrated by the flashing analysis of the river mouth gravel bars in the Monobe River due to the July 2008 flood.
|
| Free Research Field |
水工学
|
| Academic Significance and Societal Importance of the Research Achievements |
従来の側岸侵食モデルでは，側岸侵食を説明するために安息角の大きさを調節する等の簡便な手法がとられており，その普遍性に課題があった．本手法は，自立高さという観測可能な新指標を導入し，河岸材料から決まる安息角を用いて河岸侵食を解析可能にした．今後，自立高さに対する知見を蓄積することで，河口礫州の発達する河口部の流下能力等について，従来よりも信頼度の高い議論を行えるようになるものと期待できる．
|
