Development of guideline and support tools for design of inlet type driftwood trap

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02254
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: University of Toyama
• Principal Investigator: Kimura Ichiro 富山大学, 学術研究部都市デザイン学系, 教授 (60225026)
• Co-Investigator(Kenkyū-buntansha): 溝口 敦子 (寺本敦子) 名城大学, 理工学部, 教授 (40362280) ; 岡本 隆明 名城大学, 理工学部, 准教授 (70599612)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 流木 / 河川 / 河川災害

Outline of Final Research Achievements

In order to mitigate the driftwood disasters in rivers, we clarified the dynamic mechanism that governs the trapping performance of the wand (cove-like landform on the river bank) type driftwood trapping faciities and the parameters that govern the trapping ratio. It was pointed out that the trapping performance depends on the secondary current of the first kind (swirling flow that occurs at the bend of the river), the bottom surface roughness coefficient, and the density of driftwood. Furthermore, we have developed a guideline and a support tool (three-dimensional computational model for the river flow and the driftwood movement) for the design of the wando type driftwood trapping facilities.

Free Research Field

水理学

Academic Significance and Societal Importance of the Research Achievements

河川流中を移動する流木の運動特性について，水理模型実験と数値解析モデルの２つの異なる方法を用いて検討するこことで，流木運動のメカニズムを深く追求した．単に現象の解明にとどまらず，機能向上の方策や設計に資するツールの構築までをも進めた点は新規性があり，学術的な意義が大きいと考える．さらには，本研究の成果は流木減災に資する多くの情報を提供するとともに，捕捉工設計のための支援ツールとして，流水と流木を一括して三次元的に扱う数値海星モデルの提案も行っている点は社会的インパクトが大きいと考えられる．