Physics and Mathematics of Waves in Coastal Zones

This paper presents a discussion of four methods available for the computation of small amplitude periodic waves in coastal zones of arbitrary topography. With no reflections (or reflection from a single structure) the methods that proceed in space (Refraction and Propagation) or time (TJLmestep) seem the natural ones from a physical point of view. With repeated reflections, recourse must he taken to the solution of an Elliptic "boundary value problem. - It is suggested that a P-method based on (energy) flux lines and energy fronts be developed for cases where the R-methods give crossing orthogonals.