Study On China Earthquake Tsunami Hazard Analysis Based On Numerical Simulation

China coastal areas have the potential tsunami risk. Although Bohai Sea and Yellow Sea have the lower tsunami risk, East Sea and South Sea in China have the tsunamigenic conditions, which also had been suffered by the tsunami attack. Therefore, it is imminent to construct China tsunami disaster mitigation system. And researches of tsunami numerical simulation, warning system, hazard analysis must be implemented urgently. The tsunami numerical models have been developed precisely and disaster mitigation systems have been established in many countries, such as in USA and Japan, and lots of works have been done in the tsunami hazard analysis. In China, it is still in the preliminary stage.Firstly, global tsunami distributions are summarized in this paper. Based on GIS, the map of world historic tsunami distribution is given. The program is developed to simulate tsunami initial displacement field. Taken the 1960 Chile tsunami as an example, Coulomb software is deployed for verifying whether it can be as the tool of calculating tsunami initial displacements.Secondly, compared with Boussinesq equations, the linear shallow water equations are selected as governing equation of trans-oceanic tsunami propagation. Based finite difference method, trans-oceanic tsunami numerical model is also developed by FORTRAN languages. Taken 1960 Chile tsunami and 2004 Sumatra tsunami as examples, those events are used to verify this model's correctness.Thirdly, the governing equation of near-field tsunami, nonlinear shallow water equations, is solved by finite difference method and the near-field tsunami numerical model is developed by FORTRAN languages. To verify this model's correctness, it is taken the tsunami which generated at Taiwan southern sea area in 2006 as an example. By applying this model, scenario tsunami in near Ryukyu Islands is simulated. Then the calculating results are analyzed to confirm how the effects about this tsunami to eastern coastal regions of China.Fourthly, the necessity and urgency of China tsunami hazard analysis are described. Utilizing a deterministic method, from views of the slope of coastal seabed and the shape of coastline, the extent of earthquake tsunami hazard in China coastal areas is evaluated.Finally, following the similarity to the seismic hazard analysis method, the definition and method of probabilistic tsunami hazard analysis are given. Based on historic run-up data, the exceeding probability and return period of run-up in China Pearl River Delta are given.The models of trans-oceanic and near-field tsunami developed by this paper, and the works of China earthquake tsunami hazard analysis done by this paper can provide technical supports on constructing China tsunami disaster mitigation system and studying tsunami further. Those research results can also provide theoretical references on developing marine resources, protecting marine environment, and planning great engineering and facility in China coastal regions.