Low-Flow Channel Variation and Effects of Grain Sorting due to Sediment Augmentation

2009 Fiscal Year Final Research Report

• Project/Area Number: 19560521
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 水工水理学
• Research Institution: Maizuru National College of Technology
• Principal Investigator: MIWA Hiroshi Maizuru National College of Technology, 建設システム工学科, 准教授 (70190832)
• Project Period (FY): 2007 – 2009
• Keywords: 低水路 / 河床低下 / 流路変動 / 混合砂礫 / 分級 / 置き土砂 / 側岸侵食 / 平面二次元河床変動計算

Research Abstract

A sediment replenishment technology has been developed which involves the conveyance of part of the sediments excavated and/or dredged from reservoirs to the river below the corresponding dam. This technology has been implemented on a trial basis in several dam. However, this technique is in the development stage because there are many unknown factors. Therefore, systematic investigations are necessary in order to enable practical implementation and management of this technology. In this study, the effects of the location of replenished sediment on sediment flushing and on control of degradation are investigated by means of flume experiments and two-dimensional numerical simulations. The effects of grain size distribution (uniform and non-uniform sediments) on them are also discussed. The flushing process of replenishment sediments were investigated first, and then its effect on river bed degradation was analyzed.

Research Products

• [Journal Article] 置き土砂の侵食・流送と水みち変動への影響 (2009)
  • Author(s): 三輪浩, 大同淳之, 竹下洋平, 高橋拓士
  • Journal Title: 土木学会水工学論文集 53 Pages: 763-768
  • Peer Reviewed
• [Journal Article] Low-waterway variation due to change of water and sediment supply conditions (2008)
  • Author(s): Miwa, H., Daido, A., Yuasa, Y., Fujita, H.
  • Journal Title: Proc. of the 8th International Conference on Hydro-Science and Engineering Vol.VIII(CD-ROM)
• [Presentation] 固定化した水みちにおける仮置き土砂の侵食・流送過程と河床低下の改善効果 (2009)
  • Author(s): 竹下洋平, 三輪浩, 村上榮作, 山田達也
  • Organizer: 平成21年度土木学会関西支部年次学術講演会
  • Place of Presentation: 神戸工業高等専門学校
  • Year and Date: 2009-05-23
• [Presentation] 仮置き土砂が河床低下の抑制と水みちの変動に及ぼす影響 (2008)
  • Author(s): 竹下洋平, 三輪浩, 高橋拓士, 高橋剛
  • Organizer: 平成20年度土木学会関西支部年次学術講演会講演会
  • Place of Presentation: 近畿大学
  • Year and Date: 2008-05-24
• [Presentation] 仮置き土砂の侵食・流送による低水路の変動特性 (2007)
  • Author(s): 三輪浩, 高橋拓士, 竹下洋平, 工原剛正
  • Organizer: 第62回土木学会年次学術講演会講演会
  • Place of Presentation: 広島大学
  • Year and Date: 2007-09-12
• [Remarks] Miwa, H.: Effects of sediment supply on low-flow channel formation, and its variation due to sediment augmentation, Environmental Hydrology and Hydraulic Engineering seminar, Invited Lecture, Apr. 16, 2010, University of Illinois.
• [Remarks] 三輪浩:置き土による土砂供給と水みちへの影響,砂防オープンゼミ,2009年7月11日,京都大学.
• [Remarks] Miwa, H.: Effect of sediment supply conditions on low-waterway formation, International Seminar for hydrological studies on carbon and nutrient, Nov. 26, 2007, University of Hyogo.
• [Remarks] 三輪浩:仮置き土砂供給による低水路の変動特性,「河川構造物等に作用する流体力と流れ」研究分科会,2007年11月2日,京都大学穂高砂防観測所.