지진해일 전파 분산보정 유한차분모형의 정밀도 평가

Abstract

Most of finite diference numerical models for the simulation of tsunami propagation developed sofar are based on the shalow-water equations which are frequently solved by the leap-frog scheme. If the grid sizeis properly selected, this numerical scheme gives a correct dispersion effect for constant water depth. However,if the water depth changes, the dispersion effect of tsunamis can not be accurately considered at every grid pointin the whole computational domain. In this study we improved the existing two-dimensional dispersion-correction finite difference numerical scheme. The present scheme satisfies the local dispersion relationships oftsunamis propagating over a slowly varying topography while using uniform grid size and time step. To verifythe applicability of the improved numerical model, a tsunami due to 1983 East Sea central earthquake issimulated for Korean harbors with the tide gage records such as Sokcho, Mukho, Pohang and Ulsan in the EastSea. Numerical results of the 1983 tsunami are compared with the measured data and the acuracy of the presentnumerical model is evaluated.