Tide and Surge Models for Shallow Water — Morecambe Bay Revisited

Modeling of tides and storm surges in shallow coastal regions presents a number of special problems, which either do not occur at all or are less extreme in larger scale shelf seas. These problems stem from the prevalence of tidal flats (which are exposed as water levels fall and resubmerged as levels rise again), from the related process of inundation of low-lying coastal land during storm surge events, and, of course, from nonlinear effects in general, which are enhanced with decreasing water depth. The problems have long been recognized and a number of numerical schemes incorporating techniques to deal with them were proposed in the late 1960s and early 1970s, providing a basis for practical models of such regions. Flather and Heaps ¹ reviewed some of this early work and presented a simple explicit numerical method including drying and flooding of inter-tidal areas.