Depth‐integrated, non‐hydrostatic model with grid nesting for tsunami generation, propagation, and run‐up
Depth‐integrated, non‐hydrostatic model with grid nesting for tsunami generation, propagation, and run‐up
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DOI：
10.1002/fld.2485
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发表时间：
2010
影响因子：
1.8
通讯作者：
Y. Yamazaki;K. Cheung;Z. Kowalik
中科院分区：
文献类型：
--
作者：
Y. Yamazaki;K. Cheung;Z. Kowalik
地震引发的海啸涉及跨越海洋延伸到海岸的不同时间和空间尺度的物理过程。本文提出了一个在球坐标系中捕捉激波的频散波模式，用于描述整个盆地的演化和海啸的海岸抬升，并讨论了双向网格嵌套格式的实施，以描述与物理过程相适应的分辨率的波动动力学。深度积分模型描述了通过非静水压力和垂直速度的频散波，这也解释了海底动态变形产生海啸的原因。半隐式有限差分模型通过动量守恒的平流格式和迎风通量近似来捕捉与钻孔或水跃有关的流动不连续性。双向网格嵌套格式利用非静水压力的Dirichlet条件和网格间边界的水平速度和表面高程来确保色散波和不连续在不同分辨率的计算网格之间的传播。网格间边界可以适应水深特征，以最优的分辨率和计算效率模拟近岸波浪变换过程。坐标变换使模型能够应用于小的地理区域或使用笛卡尔网格的实验室实验。与深度相关的高斯函数使局部的海底地物相对于水深平滑，同时保留了对海啸转换和启动建模非常重要的水深测量。孤立波传播和N波启动的数值实验验证了网格嵌套方案的有效性。2009年萨摩亚海啸提供了一个案例研究，以证实海啸研究和影响评估的建模方法的有效性和有效性。版权所有©2010 John Wiley&Sons，Ltd.
Tsunamis generated by earthquakes involve physical processes of different temporal and spatial scales that extend across the ocean to the shore. This paper presents a shock‐capturing dispersive wave model in the spherical coordinate system for basin‐wide evolution and coastal run‐up of tsunamis and discusses the implementation of a two‐way grid‐nesting scheme to describe the wave dynamics at resolution compatible to the physical processes. The depth‐integrated model describes dispersive waves through the non‐hydrostatic pressure and vertical velocity, which also account for tsunami generation from dynamic seafloor deformation. The semi‐implicit, finite difference model captures flow discontinuities associated with bores or hydraulic jumps through the momentum‐conserved advection scheme with an upwind flux approximation. The two‐way grid‐nesting scheme utilizes the Dirichlet condition of the non‐hydrostatic pressure and both the horizontal velocity and surface elevation at the inter‐grid boundary to ensure propagation of dispersive waves and discontinuities across computational grids of different resolution. The inter‐grid boundary can adapt to bathymetric features to model nearshore wave transformation processes at optimal resolution and computational efficiency. A coordinate transformation enables application of the model to small geographic regions or laboratory experiments with a Cartesian grid. A depth‐dependent Gaussian function smoothes localized bottom features in relation to the water depth while retaining the bathymetry important for modeling of tsunami transformation and run‐up. Numerical experiments of solitary wave propagation and N‐wave run‐up verify the implementation of the grid‐nesting scheme. The 2009 Samoa Tsunami provides a case study to confirm the validity and effectiveness of the modeling approach for tsunami research and impact assessment. Copyright © 2010 John Wiley & Sons, Ltd.