Effects of water discharge and sediment supply on deformation of riverbed with sand bars

泄水供沙对沙坝河床变形的影响

• 批准号: 12650522
• 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: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650522/
• 关键词: deformation of riverbed; alternate bars; meandering streams; change of water discharge; wavelength and height; emerged bars; non-uniform sediment; grain sorting; 淵; 波長; 波高; 給砂条件; 蛇行波長

Effects of water discharge and sediment supply on deformation of sandbar beds are investigated. The effect of grain sorting on the bad deformation is also investigated. The summary of results is as follows :1. Effects of change in water discharge on growth and transformation of alternate bars(1) Effect of change rate on the transformation is relatively small in case of a long wave period, whereas it is large in case of a short one.(2) Wave height of an individual alternate bar in the non-uniform sediment bed is lower than that in the uniform one during the flood period.(3) Response-lag of the wavelength and height, flow depth and sediment transport rate to discharge change are small when the wave period is long, whereas they are large when the wave period is short. And, response-lag of alternate bars to discharge change in the non-uniform sediment bed is smaller than that in the uniform one.2. Effects of sediment supply on alternate bar transformation and meandering stream formation(1) The centralization of flow at pools of alternate bars due to decrease of water discharge makes emerged bars appear, and forms meandering streams. The meandering streams in case with sediment supply are shallow and vary actively, whereas those in case without sediment supply are deep and stable.(2) The emerged bars in the non-uniform sediment bed are formed with grain sorting, and are more stable than those in the uniform one.3. Effects of water discharge on meandering stream deformation and alternate bar reformation(1) Alternate bars are formed easily in the non-uniform sediment bed because the emerged bars in that bed are eroded easily than those in the uniform one.(2) The meandering streams are transformed into more large alternate bars by the riverbed aggradation and the low water discharge.

研究了排水量和输沙量对沙坝床变形的影响。研究了晶粒分选对不良变形的影响。结果总结如下：1。排水量变化对交替沙洲生长和转变的影响(1)变化率对交替沙洲转变的影响在波浪周期较长的情况下较小，在波浪周期较短的情况下较大。(2)汛期非均匀沙层个别交替沙坝的波高低于均匀沙层。(3)波浪周期长时，波长和高度、流深、输沙率对流量变化的响应滞后较小，波浪周期短时响应滞后较大。在非均匀沙层中，交替沙坝对流量变化的响应滞后小于均匀沙层。输沙量对交替沙洲转化和曲流形成的影响(1)由于放水量减少，交替沙洲池水流集中，使出坝出现，形成曲流。有输沙条件下曲流浅且变化活跃，无输沙条件下曲流深且稳定。(2)非均匀沉积层中的出坝是在颗粒分选过程中形成的，比均匀沉积层中的出坝更稳定。排水量对曲流变形和互变沙坝改造的影响(1)在非均匀河床中，出露沙坝比均匀河床中出露沙坝更易形成互变沙坝。(2)曲流溪流因河床淤积和低流量而形成较大的交错坝。

项目成果

Miwa, H.: "Development and transformation on alternate bars due to change of water discharege (in Japanese)"Bulletin of Maizuru National College of Technology. Vol.37. 95-106 (2002)

Miwa, H.：“由于排水量变化引起的交替坝的开发和改造（日语）”舞鹤国立工业大学通报。

Miwa, H.: "Effects of sediment supply on deformation of alternate bars and development of meandering streams (in Japanese)"Proceedings of Annual Conference of Civil Engineering 2001, JSCE Kansai Chapter. II-34 (2001)

Miwa, H.：“沉积物供应对交替坝变形和曲流溪流发展的影响（日语）”2001 年土木工程年会论文集，JSCE 关西分会。

Miwa H.: "Alternate bar transformation due to change of water discharge in graded and uniform sediment beds"Proceedings of the 5th International Conference of Hydro-Science and -Engineering. Vol.5/CD-ROM. (2002)

Miwa H.：“由于分级和均匀沉积层中水流量的变化而引起的交替坝变换”第五届国际水利科学与工程会议论文集。

Miwa, H.: "Alternate bar development and flow resistance under unsteady flow conditions (in Japanese)"Proceedigs of Annual Conference of Civil Engineers 2000, JSCE Kansai Chapter. II-38 (2000)

Miwa, H.：“非定常流动条件下的交替杆发展和流动阻力（日语）”2000 年土木工程师年会论文集，JSCE 关西分会。

三輪 浩: "流量変化による交互砂州の発達・変形過程"舞鶴工業高等専門学校紀要. 37. 95-106 (2002)

Hiroshi Miwa：“流量变化引起的交替沙洲的发育和变形过程”舞鹤国立工业大学公报37. 95-106（2002）。