Incipient motion of sediment in presence of submerged flexible vegetation

• Published in: Water Science and Engineering Vol. 8; no. 1; pp. 63 - 67
• Main Authors: Wang, Hao, Tang, Hong-wu, Zhao, Han-qing, Zhao, Xuan-yu, Lü, Sheng-qi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2015; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, PR China; Elsevier
• Subjects: Experimentation; Open channel; Sediment grain size; Sediment incipient motion; Submerged flexible vegetation; Water depth; 早期; 柔性; 水流结构; 沉水植被; 沉积物粒度; 泥沙运动; 淹没; 运动速度; Submerged flexible vegetation; Experimentation; Sediment grain size; Water depth; Sediment incipient motion; Open channel
• ISSN: 1674-2370
• DOI: 10.1016/j.wse.2015.01.002

The presence of submerged vegetation on river beds can change the water flow structure and alter the state of sediment motion. In this study, the incipient motion of sediment in the presence of submerged flexible vegetation in open channels was investigated in a laboratory experiment. The vegetation was simulated with flexible rubber cylinders arranged in parallel arrays. The effect of the vegetation density, water depth, and sediment grain size on the incipient motion was investigated. The experimental results indicate that the incipient motion velocity of sediment increases as the vegetation density decreases and the water depth and sediment grain size increase. With flexible plants, the incipient motion velocity of sediment is lower than it is without vegetation, and is larger than it is with rigid vegetation. A general incipient motion velocity equation was derived, which can be applied to both flexible and rigid vegetation conditions.