Lithologic control on the form of soil-mantled hillslopes
Lithologic control on the form of soil-mantled hillslopes
复制标题
岩性对覆土山坡形态的控制
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
G. Hilley
中科院分区：
文献类型：
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作者：
S. Johnstone;G. Hilley
在稳定的土壤覆盖景观中，坡度倾向于增加下坡，以平衡当地的输送能力和来自逐渐扩大的源区的泥沙供应。大多数由坡面过程引起的泥沙输移公式都是用局部坡度来衡量输沙率，这会产生与下伏岩性无关的凸起形式。在这项研究中，我们记录了土壤覆盖的山坡，这些山坡显示了模仿下伏地层的坡度变化。我们提供了地层和土壤厚度测量、地形分析和数值模型，以证明如果坡面运移速率随当地坡度和土层厚度变化，岩石类型的变化可以影响这些土壤覆盖的山坡的形式。这表明，在土壤覆盖的景观中形成的山坡可以通过从岩石中产生土壤的过程和将土壤向下输送的过程之间的耦合，受到下层岩性的影响。
Slopes in steady-state soil-mantled landscapes tend to increase downslope in a way that balances local transport capacity with the sediment supplied from progressively larger source areas. Most formulations of sediment transport due to hillslope processes scale transport rate with local slope, which produces convex-up forms that are independent of the properties of the underlying lithologies. In this study, we document soil-mantled hillslopes that show variations in slope that mimic the underlying stratigraphy. We present stratigraphic and soil-thickness measurements, topographic analyses, and numerical models to demonstrate that variations in rock type can impact the forms of these soil-mantled hillslopes if hillslope transport rates scale with local slope and soil thickness. This demonstrates that hillslope forms in soil-mantled landscapes can be influenced by the underlying lithology through a coupling between the processes that produce soil from rock and those that transport this soil downslope.