Brief Communication: 2-D numerical modeling of the transformation mechanism of a braided channel
Y. Xiao1, S. F. Yang1, X. Shao2, W. X. Chen3, and X. M. Xu31National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China 2Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Beijing, 100084, China 3JHD Holding, Shantou, Guangdong, 515041, China
Received: 17 Jan 2014 – Accepted for review: 07 Apr 2014 – Discussion started: 15 May 2014
Abstract. This paper investigates the controls on the transformation mechanism among different channel patterns. A 2-D depth-averaged numerical model is applied to produce the evolution of channel patterns with complex interactions among water flow, sediment transport, and bank erosion. Changes of the variables as discharge, sediment supply, and vegetation are considered in the numerical experiments, leading to the transformation from a braided pattern into a meandering one. What controls the transformation is discussed with the numerical results: vegetation helps stabilize the cut bank and bar surface, but is not a key in the transition; a decrease in discharge and sediment supply could lead a braided pattern to a meandering one. The conclusion is in agreement with various previous field work, confirming the two dimensional model's potential in predicting the transition between different rivers and improving understanding of patterning processes.
Xiao, Y., Yang, S. F., Shao, X., Chen, W. X., and Xu, X. M.: Brief Communication: 2-D numerical modeling of the transformation mechanism of a braided channel, Nonlin. Processes Geophys. Discuss., 1, 953-975, doi:10.5194/npgd-1-953-2014, 2014.