Effects of unsteady supply conditions of water and sediment and sediment sorting on variations in low-waterway morphology

水沙不稳定供给条件及泥沙分选对低水道形态变化的影响

• 批准号: 16560457
• 负责人: MIWA Hiroshi
• 金额: $ 2.37万
• 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: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560457/
• 关键词: low-watercourse; water discharge condition; sediment supply condition; unsteady; aggradation and degradation; water-route; non-uniform sediment; grain sorting; 流量・土砂供給量の変化間隔; 河床低下; 上昇; 流路変動; 土砂供給; 流量変化; 河床上昇; 低下; 河床変動; 水みち深さ; 交互砂州

Low-waterways with pool and riffle sequence functions as fish and plant habitat in ordinary discharge period. Therefore, it is important to investigate characteristics of low-waterway variation due to change of water and sediment supply conditions. This corresponds to information in order to investigate how controls of water and sediment supply are better for fish and plant habitat in rivers. In this study, effects of the change of water and sediment supply conditions on low-waterway, which developed from alternate bars, variation were investigated by means of flume tests. Results are summarized as follows :1. The low-waterways fluctuate actively along with bed aggradation during the periods of sediment supply, and they unify and stabilize along with bed degradation during the periods of no-sediment supply.2. Gentle change of sediment supply rate restricts stabilization of low-waterway, and it effects moderate variations of pool and riffle sequence.3. The low-waterway changes into alternate bars with erosion of emerged bars during the high-water discharge period ; and the alternate bars change into low-waterways with development of emerged bars during the low-water discharge period. The former occurs along with the bed degradation and the latter occurs along with the bed aggradation.4. The variation range of the depth of low-waterway in the non-uniform sediment bed is smaller than that in the uniform sediment bed because the erosion of bed sediments is restricted by means of sediment coarsening due to grain sorting.

在正常泄流期，低水位河道的滩槽序列是鱼类和植物的栖息地。因此，研究水沙条件变化引起的下水道变化特征具有重要意义。这对应的信息，以调查如何控制水和沉积物供应更好地为鱼类和植物栖息地的河流。本文通过水槽试验，研究了水沙条件变化对由交错沙坝发育而成的低汊道变化的影响。主要研究结果如下：1.在有供沙期，低潮水道沿着河床淤积波动活跃，在无供沙期，低潮水道沿沿着河床冲淤统一稳定.输沙率的平缓变化制约着下游河道的稳定，并影响着滩槽序列的适度变化.在高水流量期，低水道演变为交错沙坝，露出沙坝冲刷;在枯水流量期，交错沙坝演变为低水道，露出沙坝发育。前者沿着床层的退化而发生，后者沿着床层的淤积而发生.非均匀沙床下的航道水深变化幅度小于均匀沙床下的航道水深变化幅度，这是由于泥沙颗粒分选粗化对河床冲刷的限制。

项目成果

交互砂州河床の変動に及ぼす流量・土砂供給条件の影響

流量和供沙条件对交替沙洲河床变化的影响

• 发表时间: 2007
• 期刊: 水工学論文集 第51巻
• 作者: Miwa;H.;三輪 浩
• 通讯作者: 三輪 浩

流量変化に伴う水みちの変動過程

流量变化引起的水路波动过程

• 发表时间: 2007
• 期刊: 舞鶴工業高等専門学校専攻科特別研究報告集 第6号
• 作者: Miwa;H.;三輪 浩;藤田裕和
• 通讯作者: 藤田裕和

Effects of water discharge and sediment supply onbed variation in channel with alternate bars

隔坝河道泄水供沙对河床变化的影响

• 发表时间: 2005
• 期刊: Bulletin of Maizuru National College of Technology, (in Japanese) Vol.40
• 作者: Miwa;H.
• 通讯作者: H.

水みちの変動に及ぼす土砂供給量変化の影響

输沙量变化对水路波动的影响

• 发表时间: 2005
• 期刊: 平成17年度土木学会関西支部年次学術講演会講演概要集
• 作者: Miwa;H.;三輪 浩;三輪 浩
• 通讯作者: 三輪 浩

仮置き土砂の侵食・流送による低水路の変動特性

暂存泥沙侵蚀与搬运引起的低水道波动特征

• 发表时间: 2007
• 作者: 三輪浩;高橋拓士;竹下洋平;工原剛正
• 通讯作者: 工原剛正