为了研究床面形态物理特性对潜流交换的影响, 通过环形水槽实验, 采用概化的 2 维 离散床面形态研究了床面形态组成单元的渗透率与潜流交换通量之间的定量关联和变化特征, 并分析了床面形态组成单元的渗透率变化对有效扩散系数的影响. 实验结果表明, 床面形态组 成单元的渗透率变化对潜流交换起着不可忽视的作用. 在该实验参数变化范围内, 床面形态的 存在引入了附加的泵吸交换, 而泵吸交换对潜流交换通量的相对贡献与床面形态组成单元的 渗透率变化密切相关, 当其渗透率相对较低时泵吸交换和湍流渗透均趋于减弱, 与平整底床相 比其有效扩散系数总体上呈不同程度的减小趋势.

The influence of bedform physical properties on the hyporheic exchange process was assessed by investigating the quantitative correlation and variation between the permeability of bedform elements and hyporheic exchange flux. This investigation was conducted using laboratory annular flume experiments and conceptual two-dimensional discrete bedforms. Based on the results, it was observed that bedform permeability has a significant impact on the hyporheic exchange process. Within the bounds of the experimental parameters, the presence of bedforms was found to introduce an additional pumping exchange. The contribution of this pumping exchange to the overall hyporheic exchange flux was found to be closely related to the permeability variation in the bedform elements. When the permeability of these elements was low, the pumping exchange and turbulence penetration decreased, leading to an overall reduction in the effective diffusion coefficient when compared to scenarios with a flat bed.