基于流量过程的若尔盖黑河下游崩岸规律研究

岸坡侵蚀及岸滩崩塌对河道泥沙输移与弯道横向迁移具有重要影响。通过2017—2018年野外测量、流量频率分析和崩岸数值模拟，采用岸坡形态的原型观测数据，研究恒定和非恒定流量条件下，若尔盖高原黑河下游一个“?”型弯道的崩岸过程及其坡脚冲刷和岸坡崩塌的变化规律。恒定流量下，坡脚冲刷速率及河岸崩塌宽度随流量增大而增大。非恒定流量下，改变流量过程线的形状、峰值流量和离散度，当平均流量相同时，岸坡冲刷速率及河岸崩塌宽度基本一致，二者随平均流量的变化趋势与恒定流量下一致。这说明岸坡侵蚀的作用效果受流量大小的量级及其频率的共同作用，坡脚冲刷与岸坡崩塌主要受平均流量控制，流量过程线的形状及峰值影响较小。

Processes of bank collapse in lower Black River on Zoige Plateau based on the hydrograph

Bank erosion and collapse play an important role on sediment transport in alluvial channels and lateral migration of meandering rivers. A combination method of field measurement, discharge frequency analysis, and numerical simulation (BSTEM), based on the prototype data of bank profiles, is used to study bank failure process and bank toe erosion and collapse in a Ω-shaped bend of the lower Black on the Zoige Plateau under constant and variable discharges. The results show that under constant discharges, bank erosion rate and retreat width are increased with discharge; while under variable discharges, both are nearly the same as those under the constant discharges with the same averages and are increased with the discharge average, indicating that the bank erosion rate and retreat width are independent of the shape, peak discharge, or dispersion of hydrographs. This means that bank erosion is affected by the magnitude of discharge and its frequency, and the erosion rate of bank toe and the bank retreat width are mainly controlled by average discharge, rather than the shape of hydrograph or peak discharge.