On the effect of bathymetry in numerical storm surge simulation experiments

A numerical model is described for the simulation of storm surges which uses a non-uniform off-shore grid-spacing adjacent to coastal boundaries. This permits an increased resolution near the coast in the models described in [1,2]. Using data on the 1977 Andhra cyclone, which struck the east coast of India, it is shown that the near-coastal bathymetry is critical in determining the coastal surge-induced sea-surface elevation. It is also shown that the coastal surge response is effectively independent of the depth of water in the deepest regions of the analysis area. Conclusions are drawn concerning the selection of an optimum resolution in the numerical scheme together with the proper representation of the bathymetry