Drainage basin sensitivity to tectonic and climatic forcing: implications of a stochastic model for the role of entrainment and erosion thresholds
Drainage basin sensitivity to tectonic and climatic forcing: implications of a stochastic model for the role of entrainment and erosion thresholds
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DOI：
10.1002/esp.1020
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发表时间：
2004-02
影响因子：
3.3
通讯作者：
G. Tucker
中科院分区：
文献类型：
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作者：
G. Tucker
河道侵蚀和泥沙输送的长期平均速率取决于超过侵蚀阈值的洪水的频率-幅度特征。使用降雨和径流的泊松模型，针对存在此类阈值的情况下河流切割和沉积物输送的平均速率开发了分析解决方案。导出并数值测试了三个侵蚀/输送公式的解决方案：Howard-Kerby 剪切应力切割模型、Bridge-Dominic 沉积物输送模型和通用剪切应力沉积物输送模型。结果表明，阈值效应产生的非线性会对地形和构造和气候强迫的动态响应模式产生一阶影响。当不到一半的洪水事件能够分离岩石或沉积物时，这种非线性变得很明显。与传统的坡度线性或剪切线性侵蚀定律相比，预测的形态和隆升梯度尺度与观测和实验室实验更一致。这些结果意味着粒子脱离阈值不是长期景观演化模型中可以轻易忽略的细节。版权所有 © 2004 约翰·威利父子有限公司
Long‐term average rates of channel erosion and sediment transport depend on the frequency–magnitude characteristics of flood flows that exceed an erosion threshold. Using a Poisson model for rainfall and runoff, analytical solutions are developed for average rates of stream incision and sediment transport in the presence of such a threshold. Solutions are derived and numerically tested for three erosion/transport formulas: the Howard–Kerby shear‐stress incision model, the Bridge–Dominic sediment transport model, and a generic shear‐stress sediment transport model. Results imply that non‐linearity resulting from threshold effects can have a first‐order impact on topography and patterns of dynamic response to tectonic and climate forcing. This non‐linearity becomes significant when fewer than about half of flood events are capable of detaching rock or sediment. Predicted morphology and uplift‐gradient scaling is more closely consistent with observations and laboratory experiments than conventional slope‐linear or shear‐linear erosion laws. These results imply that particle detachment thresholds are not details that can be conveniently ignored in long‐term landscape evolution models. Copyright © 2004 John Wiley & Sons, Ltd.