床粘土对表面水的影响 - - 从波纹的波浪重建
Jonathan Malarkey1, Ellen M Pollard2, Roberto Fernández3
1School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK. j.malarkey@bangor.ac.uk.
Scientific reports
|December 27, 2024
概括
这项研究表明,沙子中的粘土含量显著影响波浪波纹尺寸. 在分析中忽视粘土可能会导致低估过去的波浪气候条件.
科学领域:
- 沉积物学的沉积物学
- 海洋学 海洋学 海洋学
- 沿海工程 沿海工程
背景情况:
- 波浪波是过去水下水力动力学条件的宝贵档案.
- 传统的方法重建波浪气候从波浪往往忽略了混合沉积床的影响.
- 最近的研究表明,沙沉积物中的粘土含量会影响波纹尺寸和运动值.
研究的目的:
- 从轨道波纹波长来确定波浪气候的清洁沙子方法,以考虑粘土的影响.
- 为了将一致的剪切应力值参数化纳入波纹分析.
- 量化粘土对波浪气候重建的影响.
主要方法:
- 修改了一种用于分析轨道波纹波长的清洁沙子方法.
- 包含粘土含量和剪切应力值参数化.
- 使用已知波形条件的当今例子验证了适应的方法.
主要成果:
- 对波浪波纹尺寸的最大粘土效应是在粗沙 (中位粒径>0.45毫米) 中观察到的.
- 与干净的沙子相比,7.4%的体积粘土度显著降低了水面波长的可能范围 (乘以三倍) 和水深 (乘以四倍).
- 这项研究强调了粘土在影响波纹形成和波浪气候重建方面的关键作用.
结论:
- 准确重建过去的波浪气候需要考虑沉积层中的粘土的存在和度.
- 在波浪波纹分析中忽视粘土含量导致低估了实际的波浪气候.
- 适应的方法为涉及混合沉积物的古海洋学和沿海工程应用提供了更强大的方法.
相关概念视频
Reflection of Waves
3.6K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
3.6K
Travelling Waves
4.9K
A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. Mechanical waves are governed by Newton's laws and require a medium to travel. A medium is a substance in which a mechanical wave propagates, and the medium produces an elastic restoring force when it is deformed.
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
4.9K
Typical Model Studies
132
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
132
Effect of Sea Water on Concrete
109
Concrete exposed to seawater can undergo degradation like the dissolution of ettringite and gypsum, increasing the material's porosity and decreasing its strength. In contrast, the crystallization of salts within the concrete's pores can cause expansion, particularly above the waterline where evaporation occurs. Nonetheless, this expansion only happens when seawater, enabled by the concrete's permeability, manages to infiltrate the structure.
Concrete in areas between tide marks,...
Concrete in areas between tide marks,...
109
Propagation of Waves
2.3K
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
2.3K
Rapidly Varying Flow
27
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
27


