Application of a diffusion‐erosion model to alluvial channels which degrade due to base‐level lowering
Application of a diffusion‐erosion model to alluvial channels which degrade due to base‐level lowering
复制标题
扩散侵蚀模型在因基准面降低而退化的冲积河道中的应用
DOI：
10.1002/esp.3290130603
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发表时间：
1988
影响因子：
3.3
通讯作者：
Z. Begin
中科院分区：
文献类型：
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作者：
Z. Begin
扩散-侵蚀模型预测退化冲积河道的瞬变纵向剖面的适用性已在实验室实验中得到证实，并在此应用于一些现场实例。通过对几条河流(流量为0.04<；Q5<；680m3s−1)的模拟纵向剖面与实测剖面的拟合，确定了扩散-侵蚀系数K，它们与流量和流域面积有很好的相关性。
通过扩散-侵蚀模型处理了基准面下降引起的临界点迎头运移。从理论上讲，从支流口到临时支点的距离应该与自基准面降低以来所经过的时间的平方根成正比。现场观测与这些理论考虑是一致的。
讨论了该模型在侵蚀预测和河流穿越的冲积断层陡坎年龄评估中的应用。
The applicability of a diffusion-erosion model that predicts transient longitudinal profiles of degrading alluvial channels has already been demonstrated in laboratory experiments, and is here applied to some field examples. By fitting simulated longitudinal profiles to measured ones for several streams (with discharge 0.04<Q5<680 m3s−1) diffusion-erosion coefficients, K, were determined which are well correlated to discharge and drainage area.
Headward knickpoint migration which results from base-level lowering was also treated through the diffusion-erosion model. Theoretically, the distance of a knickpoint from the mouth of a tributary should be proportional to the square root of the time that elapsed since the base-level was lowered. Field observations are in accordance with these theoretical considerations.
Use of the model is discussed for prediction of erosion and for assessment of the age of alluvial fault scarps crossed by streams.