海啸波近岸共振响应的数值模拟及分析

应用有限差分方法求解非线性浅水长波方程,建立了海啸波产生和传播的二维数值模型;对太平洋地震引起的夏威夷群岛海啸波进行模拟,并将模拟结果和测站实测值进行比较,验证了模型的正确性。利用快速傅里叶变换对数值模拟结果进行谱分析,得到整个计算区域的能量谱分布,并给出了发生能量聚集的位置及相应的谱峰周期。讨论了海啸波传播到近岸时可能产生的共振响应现象,发现海啸波和近岸的共振响应不仅与近岸复杂地形有关,还与海啸波传播到近岸时的波浪入射方向有关。

Numerical Simulation and Analysis of Offshore Resonance of Tsunami Waves

A two-dimensional numerical model of tsunami generation and propagation has been established by discretization of the non-linear shallow water long wave equation with the finite difference method.Tsunami waves around Hawaii islands due to Pacific earthquake were reconstructed and simulated.The simulated results show a good agreement with the data observed by tide gauge.After validation,the spectral distribution of the whole computed domain was analyzed with the Fast Fourier Transform on the simulations.Localities with strong amplification and the corresponding peak periods were revealed.The comparison with resonance from the two different directions of tsunamis shows that the resonance patterns are associated with the topographic features and the incident direction of tsunami waves.