Effect of gravel coverage on the hydrodynamic characteristics of overland flow on the Loess Plateau in China
Effect of gravel coverage on the hydrodynamic characteristics of overland flow on the Loess Plateau in China
复制标题
DOI：
10.1016/j.jhydrol.2023.130322
复制
发表时间：
2023-10
影响因子：
6.4
通讯作者：
Juanjuan Liu;Kuandi Zhang;Yong Peng;M. Rubinato;Hongyang Zhang;Pu Li
中科院分区：
文献类型：
--
作者：
Juanjuan Liu;Kuandi Zhang;Yong Peng;M. Rubinato;Hongyang Zhang;Pu Li
摘要在黄土高原地区，砾石覆盖广泛存在，研究砾石覆盖引起的土壤水动力学特性的动态变化对优化该地区的水土保持至关重要。在这项研究中，通过室内人工模拟冲刷实验，考虑10种不同的砾石覆盖度，4个坡度，和9个流量的水力参数表征的坡面流砾石覆盖的影响进行了研究。结果表明，不同实验条件下的水动力学参数差异显著（P< 0.01）。随着砾石覆盖度的增加，流动深度呈线性增加。与非砾石覆盖坡面相比，砾石覆盖坡面上的流速降低了13.62%~ 72.4%。此外，还建立了一个预测模型，以量化砾石覆盖对坡面流平均流速的影响。该模型的R2最高为0.858，RME最低为13.61%.试验结果表明，坡面流分布在“虚拟层流”-亚临界区和过渡-超临界区，砾石覆盖度和坡度对坡面流态的影响相互制约。最后，据观察，达西-韦斯巴赫阻力系数增加砾石覆盖的增加。研究结果为优化基于坡面流水动力学特征的土壤侵蚀预测模型提供了坚实的理论基础，为砾石覆盖坡面水土保持措施的合理配置提供了指导。
Abstract In the Loess Plateau of China, the presence of gravel mulching is widespread, and investigating the dynamic changes in hydrodynamic properties induced by gravel coverage is crucial for optimizing soil and water conservation in this region. In this study, the effect of gravel coverage on the hydrodynamic parameters characterizing the overland flow was investigated through indoor artificially simulated scouring experiments, considering ten different gravel coverages, four slope gradients, and nine flow discharges. The results demonstrated significant differences in hydrodynamic parameters under various experimental conditions (P< 0.01). The flow depth exhibited a linear increase with increasing gravel coverage. Compared to flow velocity observed on non-gravel-covered slope, the reduction percentage of flow velocity ranged from 13.62% to 72.4% on gravel-covered slopes. Furthermore, a prediction model was developed to quantify the impact of gravel coverage on the mean flow velocity of overland flow. The model achieved a high R 2 of 0.858 and a low RME of 13.61%. The experiments revealed that the overland flow was distributed in the “virtual laminar”-subcritical and transitional-supercritical zones, with mutual restrictions between the influence of gravel coverage and slope gradient on the flow regime. Finally, it was observed that the Darcy–Weisbach resistance coefficient increased with an increase in gravel coverage. These findings provide a solid theoretical basis for optimizing soil erosion prediction models based on the hydrodynamic characteristics of overland flow, and offer guidance for the rational allocation of soil and water conservation measures for gravel-covered slopes.