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首页> 外文期刊>Earth Surface Processes and Landforms: The journal of the British Geomorphological Research Group >Fluvial and slope-wash erosion of soil-mantled landscapes: Detachment- or transport-limited?
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Fluvial and slope-wash erosion of soil-mantled landscapes: Detachment- or transport-limited?

机译：土壤覆盖景观的河流和坡面冲刷侵蚀：分离还是运输受限？

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Many numerical landform evolution models assume that soil erosion by flowing water is either purely detachment-limited (i.e. erosion rate is related to the shear stress, power, or velocity of the flow) or purely transport-limited (i.e. erosion/deposition rate is related to the divergence of shear stress, power, or velocity). This paper reviews available data on the relative importance of detachment-limited versus transport-limited erosion by flowing water on soil-mantled hillslopes and low-order valleys. Field measurements indicate that fluvial and slope-wash modification of soil-mantled landscapes is best represented by a combination of transport-limited and detachment-limited conditions with the relative importance of each approximately equal to the ratio of sand and rock fragments to silt and clay in the eroding soil. Available data also indicate that detachment/entrainment thresholds are highly variable in space and time in many landscapes, with local threshold values dependent on vegetation cover, rock-fragment armoring, surface roughness, soil texture and cohesion. This heterogeneity is significant for determining the form of the fluvial/slope-wash erosion or transport law because spatial and/or temporal variations in detachment/entrainment thresholds can effectively increase the nonlinearity of the relationship between sediment transport and stream power. Results from landform evolution modeling also suggest that, aside from the presence of distributary channel networks and autogenic cut-and-fill cycles in non-steady-state transport-limited landscapes, it is difficult to infer the relative importance of transport-limited versus detachment-limited conditions using topography alone.
机译：许多数字地貌演化模型都假定流水对土壤的侵蚀要么是纯粹的脱离限制（即侵蚀速率与剪切应力，功率或流动速度有关），要么是纯粹的运输限制（即侵蚀/沉积速率有关）剪切应力，功率或速度的差异）。本文回顾了在土壤覆盖的山坡和低阶山谷上流水造成的限制迁移与迁移受限侵蚀相对重要性的可用数据。野外测量表明，土壤流域景观的河流和边坡冲刷改造最好用运输受限和脱离受限条件的组合来表示，每种条件的相对重要性大约等于沙子和岩石碎片与粉砂和粘土的比率在侵蚀的土壤中。现有数据还表明，在许多景观中，分离/夹带阈值在空间和时间上变化很大，局部阈值取决于植被覆盖率，岩石碎片铠装，表面粗糙度，土壤质地和内聚力。这种异质性对于确定河流/边坡冲刷侵蚀或输运规律的形式意义重大，因为分离/夹带阈值的空间和/或时间变化会有效地增加沉积物输运与流能之间关系的非线性。地形演化模型的结果还表明，除了在非稳态运输受限景观中存在分布通道网络和自生挖填循环之外，很难推断运输受限与分离的相对重要性仅使用地形的有限条件。

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