Perspective on the Tidal Bore: Background and Initiation

Tidal bores have been the subject or cause of legend, poetry, recreation, tourism, shipping disasters, and scientific interest for centuries. They pose interesting theoretical questions for the engineer. Introductory details are presented regarding the remarkable tidal bore phenomenon, including discussion of the tidal bore in various locations and a recent photograph taken by the writer of the bore on China’s Qiantang River. A supplemental tabular summary is presented based on an extensive literature review. A simplified theory based on monoclinal rising waves is developed for the initiation of the tidal bore. The theory elucidates the mechanisms of the tidal bore more clearly and completely than more complex theories. Early studies of the tidal bore are cited and discussed in historical context. The intention is to provide greater understanding of the tidal bore for a broad set of readers. The theory is favorably compared to rectangular flume data and to all field data available to the writer. A companion paper builds on the present one by addressing additional features of the tidal bore.