沉积物运输机制驱动着泥曲线中的横向积累
Runze Miao1, Alan D Howard2,3, William E Dietrich1
1Department of Earth and Planetary Science, University of California, Berkeley, CA 94720.
概括
泥的河流通过沉积泥来维持曲,这加强了河岸. 这项研究模拟了泥沉积,揭示了它取决于沉降速度和高基底度,而不仅仅是沉降与剪切速度的比率.
科学领域:
- 地球和行星科学 地球和行星科学
- 地质地质地质地质地质地
- 沉积物学的沉积物学
背景情况:
- 在火星和早期地球上发现的古老道促使人们对干旱环境道形态学的研究.
- 众所周知,泥的凝聚力可以通过减缓侵蚀和促进横向积累来实现曲.
- 在横向积累沉积沉积物中泥沉积的精确机制仍然不太清楚.
研究的目的:
- 为了研究侧向积累沉积物中的泥沉积过程.
- 在泥的曲河流域中建模侵蚀和沉积模式.
- 了解横向积累沉积物的沉积物学变化如何影响道形态.
主要方法:
- 利用Delft3D和Partheniades-Krone模型进行凝聚性沉积物运输.
- 模拟了2300米长的泥曲折的奎因河.
- 分析了沉速度,剪切速度和基底泥度对沉积的影响.
主要成果:
- 泥沉积主要是由沉速度和基底度的乘积驱动的 ([公式:见文本]).
- 显著的横向积累沉积发生,即使花沉积速度远低于剪切速度,前提是基底度很高.
- 模型准确地预测了观察到的颗粒大小分布和由升高的泥负载形成的泥间床.
结论:
- 曲的河流中的泥沉积动态是复杂的,并受到基底度的影响,而不仅仅是与剪切速度相对的沉积速度.
- 这些发现解释了泥的河流如何维持活跃的,单线曲的道.
- 泥负荷的变化可以导致各种沉积物学特征,如横向积累沉积物中的泥沙对.
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