water surface elevation is assumed to be same to the sea bed rise by an earthquake. The sea bed rise by earthquake is computed from the land fault corresponding to the specified earthquake by using the elastic body model(Manshinha and Smylie, 1971).
The Nankai Earthquake Tsunami is adopted as the model tsunami in the computer graphic. The Nankai Earthquake Tsunami occurred in 1946 and caused the heavy damages to the south-west Japan. Especially, Kochi-prefecture in Shikoku island heavily suffered from the tsunami. About 1000 people were killed by the tsunami attack in Kochi-prefecture(Takayama and Hiraishi, 1986). Another Nankai earthquake occurred in 1854. Therefore, the return period of the Nankai earthquake is considered to be about 100 〜 l50year. A large tsunami may be generated again in near future in the offshore area of the south-west Japan.
A tsunami breakwater is under construction at the Suzaki port to protect the tsunami attack. The disaster prevention planning is seriously discussed to complete Figure 3 Location of land fault the hard and soft ware to protect the port. In thecomputer graphics, we reproduce the 1946 Nankai-Earthquake Tsunami in the Suzaki port to make image information for the disaster prevention planning.
Figure 3 shows the location of land fault of 1946
Nankai Earthquake proposed by Aida(Aida,1981). Tsunami propagation is computed by resolving the finite difference expression for the continuous and momentum equations(ex. Goto,1993). The sea and land computation area is expressed by the grid topography in the finite difference method. The water surface elevation and flow flux on the computation grids are simulated with a specified time interval. The tsunami runup boundary is computed in Iwasaki and Mano model(Iwasaki and Mano,1979).
Figure 4 shows the computation area for the Suzaki-port. The grid distance in the port computation
