Aspects of a Computational Model for Long-Period Water-Wave Propagation

Derivation of a computer model for simulating the propagation of long-period waves in relatively shallow water with complex boundaries, such as in bays and estuaries, and along coastlines, and extensive experimental comparisons of simulated with real wave histories in Tokyo Bay, a Rhine estuary, and the southern North Sea. The numerical techniques apply to the propagation of water waves, such as tides, surges, seiches, tsunamis, and explosion-generated waves some distance from the explosion in shallow water. Computation is based on a new method of numerical integration of the hydrodynamic equations, taking into account vertical motion and the effects of earth rotation and ocean floor topography. Two different sets of approximations to the partial-differential equations are used successively for the step-by-step solution over time. A fast, realistic, and unconditionally stable computation can be made by the multioperation method. A computer-driven S-C 4020 microfilm recorder was used to plot the currents and water levels. A guide to the FORTRAN IV wave program enables the program to be used by hydraulic engineers without knowledge of programming. Information for making changes in the procedure is also given.