滩地植被对漫滩水流裁弯影响的实验研究  

Experimental study on the influence of riparian vegetation on the chute cutoff under overbank flow

作　　者：李贝贝[1] 李志威 胡旭跃[1] LI Bei-bei;LI Zhi-wei;HU Xu-yue(School of Hydraulic and Environmental Engineering,Changsha University of Science&Technology,Changsha 410114,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China)

机构地区：[1]长沙理工大学水利与环境工程学院,湖南长沙少410114 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072

出　　处：《泥沙研究》2023年第3期15-21,共7页Journal of Sediment Research

基　　金：国家自然科学基金项目(51979012);湖南省重大水利科技项目(XSKJ2019081-03)。

摘　　要：斜槽裁弯是弯曲河流长期演变过程中的临界地貌过程,其形态动力学过程仍缺少在不同漫滩水流和植被条件下的实验研究。以黄河源区泽曲支流浩斗曲的局部弯曲河段作为原型开展概化动床水槽实验,研究在5种漫滩水流与植被条件下的斜槽裁弯过程,分析连续弯道在裁弯前后的河床冲刷调整和平面形态变化。结果表明,斜槽裁弯由颈口处的串沟过流冲刷形成,其串沟发育位置及过程不同,颈口宽度随时间呈近似线性缩窄变化,由漫滩水流冲刷形成的新河道展宽速率最快达到129 mm/h。各工况条件下河湾内河道中心线的位置均存在不同程度的横向迁移,其速率最快达到144 mm/h。斜槽裁弯发生后,“Ω”型河湾底部的冲刷面积大于河湾顶部位置。Chute cutoff is a critical geomorphic process in the long-term evolution of meandering rivers,and is still a lack of experimental results on its morphological processes under different water flow and vegetation conditions.The generalized movable bed flume experiment was carried out with the partial sinuous reach of the Haodou River,which is a tributary of Zequ River in the Source Region of the Yellow River as the prototype,to study the processes of chute cutoff under five overbank flow and vegetation conditions.Riverbed processes and channel morphology change of continuous bends before and after chute cutoff occurrence are analyzed.Results show that chute cutoff is triggered by the overbank flow scour of the troughs at the neck,and the development position and processes of the troughs are different.The processes of neck width narrow approximately linearly with time and the widening rate of the new channel formed by the scour of the overbank flow reaches 129 mm/h at the fastest rate.There are different degrees of lateral shift in the position of the river centerline under various experimental conditions,and the fastest rate is 144 mm/h.After chute cutoff occurred,the scour area at the bottom of the"Q"shaped bend is greater than that at the apex of the bend.

关 键 词：弯曲河流 斜槽裁弯 漫滩水流 河道冲刷 滨河植被 

分 类 号：TV147.1[水利工程—水力学及河流动力学]