黄河源草甸型弯曲河流由根土层和砂砾石层共同构成典型的二元结构河岸，河岸抗剪强度、抗冲能力、破坏过程等与单层河岸比较有明显差异，其发生崩岸直接关系源区草地面积变化、弯道的横向演变速率和长期形态动力过程，因此对其崩岸机制和力学模型的研究具有重要的实际意义和理论价值。本项目拟以黄河源区泽曲和兰木措曲为研究对象，采用室内外试验相结合的方法，重点开展不同河岸物质组成的砂砾石层抗冲试验、根-土层原位剪切试验和根系原位拉拔试验，并结合弯曲河道GPS-RTK地形测量，定量分析二元结构河岸的受力特点、砂石层淘蚀过程、淘蚀速率与根-土层抗拉增强作用对河岸崩岸模式、崩岸速率和崩塌尺寸的影响，揭示源区曲流崩岸过程及影响河岸崩塌的关键因素，并建立考虑冻融作用和根系加筋作用的崩岸力学模型。本研究将有助于加深对草甸型弯曲河道演变规律的认识，为黄河源区的河道保护和稳定方案提供科学参考。

Meadow meandering river is characteristics of typical composite bank constituted by soil-root layer and sand gravel layer in source region of the Yellow River, this made great differences in shear strength, anti-scouring ability and bank failure processes of river bank compared with single layer bank structure. Its bank failure is directly related to the grassland area change, lateral fluvial process and dynamic process of long-term river morphology of the Yellow River source region, so this research of bank failure mechanism and mechanical model of meadow meandering river have important practical significance and theoretical value. The project plan to take Zequ and Lanmucuoqu as the study object, and emphatically carry out scouring experiments of sand and gravel layer of different particle size range, in situ shear tests of soil-root layer and pull-out tests of single root of riparian vegetation, and through the combination with topographic survey by GPS-RTK technique. Some influences upon bank failure pattern, speed and size will be made quantitative analyses, the influence factors include bearing force characteristics of composite bank, scouring process of sand and gravel layer, erosion velocity and tensile reinforcement of soil-root composite. Moreover, it is to reveal and analyze the bank failure process and key factors, and establish the theoretical model considering freeze-thaw action and root system reinforcement. Our studies will deepen understanding of channel evolution of meadow meandering river and provide scientific references for channel protection and stabilization scheme in source region of the Yellow River.