滨水植被对河流弯道水流结构及泥沙输移影响机理研究

项目名称： 滨水植被对河流弯道水流结构及泥沙输移影响机理研究

项目编号： No.11472310

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 曹文洪

作者单位： 中国水利水电科学研究院

项目金额： 90万元

中文摘要： 作为河流生态系统的重要组成部分，滨水植被对于保持生物多样性、维持河流健康具有重要作用；现有研究表明，滨水植被在蜿蜒型河道演变中起着关键作用。深入研究植被对水流运动和泥沙输移的影响，不仅对于完善和丰富河流动力学、河床演变学有重要的理论意义，而且可为河流生态修复及综合管理提供关键技术支撑。现有关于植被对水沙输移影响研究多基于顺直水流，对于自然界普遍存在的弯道则涉及较少。针对上述研究现状，本项目拟通过系列弯道水槽试验，并结合流体力学边界层理论、紊流力学、河流动力学及河床演变学理论，对植被作用下的弯道水流及泥沙输沙进行深入研究，定量识别植被作用下弯道环流的产生及消亡过程，揭示弯曲水流条件下植被区内、植被区外的流速分布、紊动耗散、雷诺应力、紊流相干结构及床面切应力分布规律；探求植被对弯道的纵横向输沙、横断面的冲淤形态影响的量化途径，揭示植被对弯道水沙输移影响机理。

中文关键词： 河流动力学；泥沙输移；弯曲型河道；河床演变；滨水植被

英文摘要： As an important part of the ecosystem of the river, riparian vegetation has an important role to maintain biodiversity of the ecosystem and preserving the health of the river. Moreover, existing large number of studies have shown that riparian vegetation also plays a key role in the fluvial process. Therefore, intensively study on the impact of vegetation on flow and sediment transport has important theoretical significance and practical value; it would not only improve and enrich the fluvial process theory, but also provide technical support for river restoration and management. Existing research on effect of vegetation on flow and sediment transport are mostly based on straight flow, whereas the ubiquitous nature of the river meander is less involved. In response to these research status, the proposed project intends to carry out a series experiments in a curve flume, combined with boundary layer theory in fluid mechanics, mechanics of turbulence, river dynamics, sediment transport and fluvial process theory, to get a deep insight on the curved vegetation flow, quantitative identification of vegetation effects on the initiation and decay of the secondary flow, revealing the velocity profile between and outside of the vegetation area, the turbulent dissipation, Reynolds stress, turbulent coherent structures and bed shear stress distribution. Additionally, we will also explore the effect of vegetation on the direction of the sediment transport and the erosion and deposition morphology of the cross section, and an initial theoretical system about the vegetation and sediment transport in a curved flow would establish through this study.

英文关键词： river mechanics;sediment transport;meander;fluvial process;riparian vegetation