Shallow water equation is widely used in tsunami early warning and researches ,however ,it is necessary to know the application scope and calculation efficiency of linear and nonlinear shallow w ater equations under different topographical and bathymetrical conditions .This paper mainly studied the linear and nonlinear characteristics of tsunami waves propagating in the South China Sea and the East China Sea with the continental shelf effects by u -sing tsunami numerical forecasting model w hich w ere developed based on shallow w ater equations . Propagation characteristics of tsunami waves in the deep water show strong linear features (A/H《1) .The simulation of tsu-nami wave amplitude has high precision and efficiency under this linear system ,whereas the characteristics of weak nonlinear and dispersion have small effect on the simulation of tsunami that can be ignored .Due to the variation of seafloor gradient and roughness effect ,when tsunami waves propagates to the shallow water continental shelf ,non-linear effect on the waves will travel and accumulate rapidly .It shows a significant difference comparing to the tsu-nami wave simulations that uses linear and nonlinear shallow water equations .The results showed that in the South China Sea where the water depth is lower than 100 m ,the nonlinear effects on waves following the first wave of a tsunami were evident and different but a small effect on the first wave .Hence ,to use the linear system simula-ting tsunami wave amplitudes can meet the tsunami early warning requirements without the consideration of tsuna-mi inundation .In the East China Sea ,because of the continental shelf ,it is critical to consider nonlinear characteris-tics since first wave and later phase wave of a tsunami were significant different which were simulated by linear and nonlinear tsunami numerical models respectively .This paper also highlighted the numerical comparison study of bottom friction term effect on tsunami initial wave amplitude .The results showed that bottom friction effected the area only with water depth less than 100 m .Finally ,we preliminarily analyzed the effect of continental shelf width on maximum tsunami amplitude based on the sensitivity tests .It can be summarized w hen tsunami w aves propa-gate and deform at continental shelf ,the maximum tsunami amplitude must be weakened by the East China Sea continental shelf is not correct .Whether the tsunami amplitude will enlarge or reduce is mainly depends on the continental shelf width and the depth of outer margin of the continental shelf .%浅水方程被广泛应用于海啸预警报业务及研究，而针对线性浅水方程与非线性浅水方程在不同海区水深地形条件下的适用范围、计算效率问题是海啸研究人员急需了解的。本文应用基于浅水方程的海啸数值预报模型就海啸波在南海、东海传播的线性、非线性特征以及陆架对其传播之影响进行了数值分析研究。海啸波在深水的传播表征为强线性特征，此时线性系统对海啸波幅的模拟计算具有较高的精度和效率，而弱的非线性特征及弱的色散特征对海啸波幅的预报影响甚微，可以忽略不计。海啸波传播至浅水大陆架后受海底坡度变化、海底粗糙度等因素影响，波动的非线性效应迅速传播、积累，与线性浅水方程计算的海啸波相比表现出较大差异，主要表现为：在南海区，水深小于100 m时，海啸波首波以后的系列波动非线性特征比较明显，两者波幅差别较大，但首波波幅的区别不大，因此对于该区域在不考虑海啸爬高的情况下，应用线性系统计算得到的海啸波幅也可满足海啸预警报的要求；在东海区由于陆架影响，海啸波非线性特征明显增强，水深小于100 m区域，首波及其后系列波波幅均差异较大，故在该区域必须考虑海啸波非线性作用。本文就底摩擦项对海啸波首波波幅的影响进行了数值对比分析，结果表明：底摩擦作用对海啸波首波波幅影响仅作用于小于100 m水深。最后，该文通过敏感性试验，初步分析了陆架宽度及陆架边缘深度对海啸波波幅的影响，得出海啸波经陆架传播共振、变形后，海啸波幅的放大或减小与陆架的宽度及陆架边缘水深有关。
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