Effects of water and sediment discharge conditions on variation in sand bar morphology

排水排沙条件对砂坝形态变化的影响

• 批准号: 14550518
• 负责人: MIWA Hiroshi
• 金额: $ 2.3万
• 依托单位: Maizuru National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550518/
• 关键词: deformation of riverbed; alternate bars; low-watercourse; degradation; aggradation; changing rate of bed slope; wavelength and height; non-uniform sediment; grain sorting; 給砂量; 上昇; 波長; 波高; 淵

Many studies on alternate bars have been conducted under an equilibrium sediment supply condition which corresponds to the water discharge, and discussed phenomena in an equilibrium state. However, bar morphology in rivers are not always formed under such condition. Therefore, it is important to investigate how the bar morphology formed by some water and sediment discharge condition varies by the other conditions. In this study, effects of rotational degradation/aggradation caused by an imbalance between water and sediment transport capacity on variation in alternate bar morphology are investigated in uniform and non-uniform sediment beds. Effect of grain sorting on the variation is also discussed. Results are summarized as follows :1.In case that the degradation progresses under the condition of small-water discharge near the double-low bar formation regime, the wavelength of alternate bars increases gradually because the areas with little sediment transport develop. When the degradat … More ion progresses further, both of the wavelength and height increase because low watercourse develops.2.In case that the degradation progresses under the large-water discharge near the no-bar formation regime, the wavelength and height decrease because the development of alternate bars is restricted. In particular, the alternate bar development is unstable in the non-uniform sediment bed.3.In case that the aggradation progresses under the large-water discharge near the no-bar formation regime, the wave length increases gradually because the development of alternate bars is promoted.4.The increase and the decrease of wavelength and height of alternate bars in consequence of the degradation are remarkable in the non-uniform sediment bed.5.Not only bed slope but also its changing rate affects variations in bar morphology.6.The migration velocity of bars decreases with degradation, and that increases with aggradation. The decrease of migration velocity relates to immobilization of pools and the formation of a low-watercourse. Less

许多关于交替坝的研究都是在与排水量相对应的平衡供沙条件下进行的，并讨论了平衡状态下的现象。然而，河流中的坝形态并不总是在这种条件下形成的。因此，研究某些水和泥沙排放条件下形成的坝体形态如何随其他条件的变化是很重要的。在这项研究中，研究了均匀和非均匀沉积物床中水和沉积物输送能力之间的不平衡引起的旋转降解/沉积对交替坝形态变化的影响。还讨论了谷物分选对变异的影响。结果如下： 1.在双低坝形成区附近小流量条件下的退化过程中，由于泥沙搬运较少的区域发育，交替坝的波长逐渐增大。当降解离子进一步进展时，由于低水道发育，波长和高度均增加。2.在无坝形成区附近的大水流量下降解进行时，由于交替坝的发育受到限制，波长和高度减小。特别是，在非均匀沉积层中，交错坝的发育是不稳定的。 3.在无坝形成区附近的大水流量下，淤积过程中，由于促进了交错坝的发育，波长逐渐增大。 4.在非均匀沉积层中，退化引起的交错坝的波长和高度的增加和减少是显着的。 5.不仅是床坡，其坡度也明显增加。 变化率影响棒形态的变化。6.棒的迁移速度随着降解而减小，随着沉积而增加。运移速度的降低与水池的固定和低水道的形成有关。较少的

项目成果

Effect of sediment supply on alternate bar deformation and meandering streambed formation

泥沙供给对交替坝变形和曲流河床形成的影响

• 发表时间: 2004
• 期刊: Proceedings of the 9th International Symposium on River Sedimentation III
• 作者: Miwa;Hiroshi
• 通讯作者: Hiroshi

Deformation of meandering streams and formation of alternate bars

蜿蜒水流的变形和交替坝的形成

• 发表时间: 2004
• 期刊: Annual Journal of Hydraulic Engineering, JSCE (in Japanese) Vol.48
• 作者: Miwa;H.
• 通讯作者: H.

交互砂州の変形と水みちの形成に及ぼす給砂の影響

供沙对交错沙洲变形及水道形成的影响

• 发表时间: 2003
• 期刊: 舞鶴工業高等門学校紀要 38
• 作者: Miwa;H.;三輪 浩
• 通讯作者: 三輪 浩

三輪 浩: "交互砂州河床の変形に及ぼす河床上昇/低下の影響"平成16年度土木学会関西支部年次学術講演会講演概要集. II-46 (2004)

Hiroshi Miwa：“河床上升/下降对交替沙洲河床变形的影响”2004年日本土木工程学会关西分会年度学术讲座摘要集II-46（2004）。

水みちの変形と交互砂州の発達過程

水路变形及交替沙洲发育过程

• 发表时间: 2004
• 期刊: 水工学論文集 48
• 作者: 三輪 浩