若尔盖高原泥炭型弯曲河道崩岸过程模拟

崩岸在河床演变和河型转化中发挥重要作用，促使河岸横向移动和河道蜿蜒。2011—2016年黄河源若尔盖高原的弯曲河流野外调查表明，泥炭型弯曲河流的崩岸是河岸上部泥炭层在自重作用下发生的悬臂式崩岸。针对泥炭型河岸的悬臂式崩岸，采用BSTEM模型分析其岸坡稳定性，并模拟河岸侵蚀和崩塌过程。泥炭层的含水率是河岸稳定的关键因子，泥炭层含水率的增加，既增强河岸崩塌的驱动力，也减弱抵抗河岸崩塌的抗剪力，对河岸稳定不利。河岸二元物质组成的厚度对河岸稳定性有较大影响，其泥炭层厚度的增加，可提高河岸稳定性，但是河岸下部粉沙层厚度的增加，则会降低河岸的稳定性。

Conceptually modelling of cantilever bank failure processes of peat-type meandering channel in the Zoige Plateau

Bank failure plays a vital role in fluvial processes and river pattern transformation in meandering rivers, driving lateral migration and increasing channel sinuosity. Field surveys on meandering rivers of the Zoige Plateau in the Yellow River source region during 2011-2016 demonstrated that the bank failure in the outer bank is the cantilever pattern in the peat-type meandering river, but the processes of this cantilever bank failure is little known so far. To analyze the cantilever bank failure, the Bank Stability and Toe Erosion Model (BSTEM) is applied to study the stability of bank and slope, and to simulate bank erosion and collapsing processes. The stability of the peat-type bank is closely related to the water content of the peat layer. If the water content increases, not only the driving force of bank failure is strengthened, but also the shearing resistance is weakened, which is unfavorable to the stability of the peat-type bank. The thickness of two-layer bank material has an important influence on the bank stability. The increasing of the peat layer thickness strengthens the bank stability, whereas the increasing of silt layer thickness reduces the stability.