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Numerical Evaluation of Tsunami Wave Hazards in Harbors along the South China Sea. Huimin H. Jing 1 , Huai Zhang 1 , David A. Yuen 1, 2, 3 and Yaolin Shi 1 1 Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences
Huimin H. Jing 1, Huai Zhang1, David A. Yuen1, 2, 3 and Yaolin Shi 1
1Laboratory of Computational Geodynamics,
Graduate University of Chinese Academy of Sciences
2Department of Geology and Geophysics, University of Minnesota
3Minnesota Supercomputing Institute, University of Minnesota
2. Numerical experiments
2.1 Governing equations
2.2 Finite difference scheme
2.3 Numerical Model
3. Results and conclusions
The probability of tsunami hazards in South China Sea.
The Manila Trench bordered the South China Sea and the adjacent Philippine Sea palate is an excellent candidate for tsunami earthquakes to occur.
The coastal height along the South China Sea is generally low making it extremely vulnerable to incoming waves with a height of only a couple meters.
The results of the probabilistic forecast of tsunami hazard show the region where the wave height is higher than 2.0m and between 1.0-2.0m with a grid resolution of around 3.8km (Y. Liu et al. 2007).
In order to investigate the wave hazard in the harbors, simulations in higher precise are needed……
Shallow water equations
Conventional Boussinesq equations
Deep water wave
Shallow water wave
L < 2h
L > 20h
Extended Boussinesq equations
is the basic parameter in the theory of shallow water model：
where C is a constant.
derivatives of h(x,y,t)
The data of the compute area is comprised by topography data on the land (SRTM3, with a grid resolution of around 90m ) and bathymetry data of the seabed (SRTM30, with a grid resolution of around 900m ) .
In our numerical model, the grid size of the computational area is about 50m while the time step is 0.05s.
When the tsunami comes from far field, the incident waves near the harbor area can be approximately considered as plane waves.
Plane wave function is as following:
Supposed the wave height is about 1m in the far field ocean, and carried on our simulations on the actual bathymetry data with the wave propagation packages.
The reflection, diffraction and interference phenomenon of the waves are illustrated by the animations.
Water surface elevation track recorder points
The time series data of the water level vary with time have been recorded.
3.Results and conclusions
By doing comparisons in the cases with different incident waves at the same point we get the effects of wave direction.
By doing comparisons in the same incident wave case at different recorder points we get the effects of water depth.
The numerical simulations can be conducted to evaluate the reasons of harbor hazards and investigate the effects of different incident waves.
The direction of incident waves affect the wave hazard in a harbor.
The wave height in the coast area would be 7-8 times higher than it is in the ocean.
Water depth is the significant factor which affects the wave height.
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