Variability of hydraulic characteristics of sediment-laden rill flow under various slopes, water flows and sediment loads

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena Pub Date : 2025-05-12 DOI:10.1016/j.catena.2025.109134

Chunhong Zhou , Nan Shen , Fengbao Zhang , Dongyuan Li , Feng Jiao

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引用次数: 0

Abstract

During soil erosion, sediment load of rill flow changes dynamically and may affect its hydraulic characteristics. However, current research on hydraulics of sediment-laden rill flow primarily uses river sand/artificial homogeneous materials as sediment, which significantly differ from natural soil, leaving a research gap on how soil quantity impacts rill flow hydraulics. This study uses natural soil in an indoor rill flume simulation experiment to explore how sediment load influences hydraulic characteristics of rill flow, including flow velocity (V), Darcy–Weisbach friction coefficient (f), Reynolds number (Re), Froude number (Fr), and flow depth (h). Experiments were conducted under combinations of six different sediment loads, five flow discharges, and five slopes. The results indicated that V, f, Re, Fr were significantly influenced by sediment concentration. V and Fr show an upward trend as the sediment load increases, while f, Re, and h demonstrate a downward trend. The sediment load predominantly influences V, f, and Fr, accounting for contributions of 0.33, 0.49, and 0.39, respectively. The influence of slope gradient on V and Fr intensifies as the sediment load increases, while the impact of flow discharge on V, f, and Fr diminishes. As flow discharge increases, the effect of sediment load diminishes on V and Fr, and that of slope gradient strengthens. Two kinds of prediction equations were developed for estimating the hydraulic parameters of sediment-laden rill flow. The models demonstrate high R² values (0.74 to 0.98), suggesting strong performance of the prediction equations. These findings lay a foundation for the better development of a physical process-based rill erosion model. Given the differences in the properties of natural soils, which may impact hydraulic characteristics, it is a limitation of this study that it only focuses on a single soil type, and thus future research should explore the effect of sediment properties on hydraulic characteristics.

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不同坡度、水流和泥沙荷载下含沙细流水力特性的变化

在土壤侵蚀过程中，细沟水流的输沙量是动态变化的，会影响其水力特性。然而，目前对含沙细流水力学的研究主要是采用河砂/人工均质材料作为泥沙，与天然土有很大的不同，土壤数量对细流水力学的影响存在研究空白。本研究利用天然土进行室内细沟水槽模拟实验，探讨泥沙荷载对细沟水流水力特性的影响，包括流速(V)、达西-韦斯巴赫摩擦系数(f)、雷诺数（Re）、弗劳德数（Fr）和流深(h)。试验在6种不同泥沙负荷、5种流量和5种坡度的组合下进行。结果表明，V、f、Re、Fr受沉积物浓度影响显著。随着泥沙负荷的增加，V和Fr呈上升趋势，而f、Re和h呈下降趋势。泥沙负荷主要影响V、f和Fr，贡献率分别为0.33、0.49和0.39。坡度对V和Fr的影响随着泥沙负荷的增加而增强，而流量对V、f和Fr的影响减弱。随着流量的增加，泥沙荷载对V和Fr的影响减弱，坡度的影响增强。建立了两种含沙细沟水流水力参数的预测方程。模型显示出较高的R2值（0.74 ~ 0.98），表明预测方程具有较强的性能。这些发现为更好地建立基于物理过程的细沟侵蚀模型奠定了基础。由于天然土壤性质的差异可能会影响水力特性，因此本研究仅针对单一土壤类型存在局限性，未来的研究应进一步探讨泥沙性质对水力特性的影响。

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来源期刊

Catena 环境科学-地球科学综合

CiteScore

10.50

自引率

9.70%

发文量

816

审稿时长

54 days

期刊介绍： Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment. Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.