Experimental Study on Hydraulic Roughness of Submerged Grass in Ecological Riverbank

Abstract:

A model experiment about the hydraulic roughness of natural turf used in riverbank was carried out in flume. To examine the rationality of experimental design, the hydraulic roughness coefficient of plexiglass-flume was tested firstly. The result was 0.0085, which is quite normal. Then the tested hydraulic roughness caused by vegetation ranges from 0.020 to 0.090 for the chosen plants, which is also acceptable. Furthermore, the tested incipient velocities of krasnozem, and paddysoil had the range of 0.55~0.65m·s^-1 and 1.0~1.1m·s^-1, respectively. All these experimental results are in normal range, which means that the design of this experimental is rational. Experimental research illustrate that, the roughness coefficient of plant reduces with the increasing of flow velocity. When the mean flow velocity is over 3m·s^-1, Mannings n values vary between 0.025 and 0.035. This phenomenon is accord with the theoretic analysis. During the scouring process, not only the flow velocity, but also the flow duration has an obvious effect on the coarseness of vegetative bed.

• Periodical: Advanced Materials Research (Volumes 838-841)
• Pages: 1743-1748
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.838-841.1743
• Online since: November 2013
• Authors: Dian Guang Ma, Chun Xin Zhong, Wu Ning, Qing Ye, Sheng Zhu
• Keywords: Experimental Research, Flow Velocity, Hydraulic Roughness, Riverbank, Scour, Vegetation

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