Nodes, widely exist in bifurcated channels, have essential impact on river bed evolution. We explored the impact of nodes on bifurcated channel evolution and provided guidance for river regulation by combining mathematical modelling and riverbed evolution analysis. Madang reach, which lies in the downstream of Yangtze River, is a typical slightly-bent and bifurcated channel. Many sandbars or shoals bifurcate this reach, such as Gupaizhou sandbar, Mianwaizhou shoal and Guazihaozhou sandbar. There are some nodes formed by mountains in Madang Reach, like Xiaogushan, Penglangji, Madangji, and Madangzui. A 2-D mathematical model of Madang reach was established and verified. From the perspective of water flow and riverbed evolution, the impact of sub-branches’ diversion ratio variation on their upstream and downstream channels, and the nodes’ influence on riverbed evolution were further analysed. Results reveal that by controlling the node of Xiaogushan-Penglangji, the incoming flow at the inlet of Madang reach is stable, and is slightly affected by its upstream variation. Due to the modification of Madangji-Madangzui node, when the diversion ratio of Mianwaizhou shoal varies from 23.3% to 58.1%, its impact on main flow and river bed erosion & deposition only covers a limited distance of 2-2.5km downstream of Madangji.
ZUO Li-qin
,
LU Yong-jun
. Effect of Nodes on Branch Evolution in Madang Reach in the Downstream of Yangtze River[J]. Journal of Changjiang River Scientific Research Institute, 2014
, 31(10)
: 72
-79
.
DOI: 10.3969/j.issn.1001-5485.2014.10.011
[1] 余文畴. 长江下游分汊河道节点在河床演变中的作用[J].泥沙研究, 1987, (4): 12-21. (YU Wen-chou. Action of Nodes of the Braided Channel at the Lower Yangtze River in the Fluvial Processes [J]. Journal of Sediment Research, 1987, (4): 12-21. (in Chinese))
[2] 钱 宁, 张 仁, 周志德. 河床演变学[M]. 北京: 科学出版社, 1987. (QIAN Ning, ZHANG Ren, ZHOU Zhi-de. Riverbed Evolution [M]. Beijing: Science Press, 1987. (in Chinese))
[3] 夏修杰, 张林忠, 王恺忱. 河道中的节点[C]∥第七届全国泥沙基本理论研究学术讨论会论文集, 2008: 451-454. (XIA Xiu-jie, ZHANG Lin-zhong, WANG Kai-chen. Nodes in Rivers [C]∥Proceedings of the 7th National Academic Conference on Sediment Basic Theory Research, 2008: 451-454. (in Chinese))
[4] 王昌杰, 陈国祥.河流动力学[M].北京: 人民交通出版社, 2001. (WANG Chang-jie, CHEN Guo-xiang. River Dynamics [M]. Beijing: China Communications Press, 2001. (in Chinese))
[5] 夏细禾, 颜国红.长江中下游分汊河道稳定性研究[J].长江科学院院报, 2000, 17(5):9-18. (XIA Xi-he, YAN Guo-hong. Study on Stability of Branch Channels on Middle and Lower Reaches of Yangtze River [J]. Journal of Yangtze River Scientific Research Institute, 2000, 17(5):9-18. (in Chinese))
[6] 姚仕明, 张 超, 王 龙,等.分汊河道水流运动特性研究[J].水力发电学报,2006, 25(3): 49-57. (YAO Shi-ming, ZHANG Chao, WANG Long, et al. Study on the Characteristics of Flow Movement in Branching River [J]. Journal of Hydroelectric Engineering, 2006, 25(3): 49-57.(in Chinese))
[7] 潘庆燊,胡向阳.长江中下游分汊河段的整治[J].长江科学院院报, 2005, 22(3): 13-17. (PAN Qing-shen, HU Xiang-yang. Bifurcated Channel Stretches Regulation in Middle and Lower Yangtze River [J]. Journal of Yangtze River Scientific Research Institute, 2005, 22(3): 13-17. (in Chinese))
[8] 窦 臻, 张增发.长江和畅洲左汊潜坝工程对汊道演变的影响[J].长江科学院院报, 2012, 29(10): 21-27. (DOU Zhen, ZHANG Zeng-fa. Effect of Submerged Dike in the Left Branch at Hechang Sandbar on the Evolution of River Branches [J]. Journal of Yangtze River Scientific Research Institute, 2012, 29(10): 21-27. (in Chinese))
[9] 顾 莉, 华祖林, 褚克坚, 等.顺直微弯型分汊河道水流的紊动特性试验研究[J].河海大学学报, 2011, 39(5): 475-481. (GU Li, HUA Zu-lin, CHU Ke-jian, et al. Experimental Study on Turbulence Characteristics of Flow in Straight or Slightly Curved Braided Rivers [J]. Journal of Hohai University, 2011, 39(5): 475-481. (in Chinese))
[10]张 为, 李义天, 江 凌. 三峡水库蓄水后长江中下游典型分汊浅滩河段演变趋势预测[J]. 四川大学学报: 工程科学版, 2008, 40(4): 17-24. (ZHANG Wei, LI Yi-tian, JIANG Ling. Fluvial Process Change of the Typical Multi-Branched Meandering Reach in the Mid-Down Yangtze River After Three Gorges Dam Impoundment[J]. Journal of Sichuan University (Engineering Science), 2008, 40(4): 17-24. (in Chinese))
[11]LU Yong-jun, WANG Zhao-yin, ZUO Li-qin. 2D Numerical Simulation of Flood and Fluvial Process in the Meandering and Island-braided Middle Yangtze River[J]. International Journal of Sediment Research,2005, 20(4): 333-349.
[12]陆永军, 陈国祥. 航道工程泥沙数学模型的研究(I)——模型的建立[J]. 河海大学学报, 1997, 25(6): 8-14. (LU Yong-jun, CHEN Guo-xiang. Study on Sediment Mathematic Model for Waterway Engineering (I)-Development of the Model [J]. Journal of Hohai University, 1997, 25(6): 8-14. (in Chinese))
[13]南京水利科学研究院. 长江下游马当河段航道整治工程平面二维水沙数值模拟研究[R]. 南京: 南京水利科学研究院, 2008. (Nanjing Hydraulic Research Institute. Study on 2D Mathematic Model for Flow and Sediment Transport in Madang Reach Downstream Yangtze River [R]. Nanjing: Nanjing Hydraulic Research Institute, 2008. (in Chinese))
