Flooding and flow path selection on alluvial fans and deltas
Flooding and flow path selection on alluvial fans and deltas
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DOI：
10.1029/2009gl041985
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发表时间：
2010-03
影响因子：
5.2
通讯作者：
M. Reitz;D. Jerolmack;J. Swenson
中科院分区：
文献类型：
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作者：
M. Reitz;D. Jerolmack;J. Swenson
冲积扇和河流三角洲（统称为扇）的表面经常被少量从扇顶辐射的通道分割。在较长的时间尺度上，河道通过撕脱迁移，这是一个河床沉积和废弃的过程，通常会导致灾难性的洪水和人口稠密的风扇上的生命损失。我们提出的实验风扇，通过撕脱创造现实的通道模式的结果。撕脱循环的周期可以根据质量守恒定律预测。新流动路径的选择本质上是随机的;然而，一旦建立了4-5个通道的网络，流动就在这些通道之间无限地振荡。我们证明了有向随机游走模型与记忆定量再现这些动态和限制行为，是一致的自然风扇。
The surfaces of alluvial fans and river deltas (collectively fans) are often dissected by a small number of channels radiating from the fan apex. On long timescales, channels migrate via avulsion, the process of channel bed deposition and abandonment that often results in catastrophic flooding and loss of life on densely populated fans. We present results of an experimental fan that creates realistic channel patterns by avulsion. The avulsion cycle occurs with a period that is predictable from conservation of mass. Selection of a new flow path is inherently stochastic; however, once a network of 4–5 channels is established, flow oscillates among these channels indefinitely. We demonstrate that a directed random walk model with memory quantitatively reproduces these dynamics and limiting behavior, and is consistent with natural fans.