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

在与流量相对应的平衡供沙条件下，对交错沙坝进行了许多研究，并讨论了平衡状态下的现象。然而，河流中的沙洲形态并不总是在这种条件下形成的。因此，研究水沙条件下形成的拦门沙形态在其他条件下的变化规律具有重要意义。在这项研究中，旋转退化/加积造成的水沙输运能力之间的不平衡，在交替的酒吧形态的变化的影响进行了研究，在均匀和不均匀的沉积床。本文还讨论了颗粒分选对这种变化的影响。研究结果表明：1.在小流量条件下，当双低沙坝形成区附近的河道退化过程进行时，由于少沙区的发育，交错沙坝的波长逐渐增大。当降解产物 ...更多信息 2.在大流量条件下，无拦门沙形成区附近，由于交错拦门沙的发育受到限制，当拦门沙形成区附近出现大流量时，由于拦门沙的发育受到限制，拦门沙的波长和高度均减小。特别是在非均匀沙床中，交错沙坝的发育是不稳定的。4.在非退化区，退化引起的交错沙坝的波长和高度的增加和减少都是显著的，而在非退化区，交错沙坝的波长和高度的增加和减少是显著的。沙坝形态的变化不仅受河床坡度的影响，而且受河床坡度变化速率的影响。沙坝迁移速度随河床的退化而减小，随河床的淤积而增大。运移速度的降低与水库的固定和低水位河道的形成有关。少

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