The response of spit shapes to wave-angle climates

Journal Article

We investigate spit formation and evolution in light of the high-wave-angle instability in shoreline shape arising from a maximizing angle for wave-driven alongshore sediment transport. Single spits emerge in a simple one-contour line numerical model that evolves the coast using morphodynamic feedbacks and a 'climate' of waves approaching the shore from variable directions. Analysis of sediment transport and shoreline stability metrics illustrate how spits can be generated, demonstrating how waves from all angles can play a role in spit formation and evolution. Simulations suggest that regardless of whether high- or low-angle waves dominate relative to the general shoreline trend, as spits extend offshore, they tend to orient themselves such that most of their coast barely experiences low-angle waves and alongshore sediment transport to the spit end is maximized. This 'graded' spit shape minimizes gradients in sediment flux, while the recurve at the spit end experiences larger gradients and a region of high-angle instability. Examining hindcast wave data, similar trends are seen along the natural example of Long Point, Lake Erie, Canada. © 2007 ASCE.

Full Text

Duke Authors

Cited Authors

  • Ashton, AD; Murray, AB; Littlewood, R

Published Date

  • September 17, 2007

Published In

  • Coastal Sediments '07 Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes

Digital Object Identifier (DOI)

  • 10.1061/40926(239)27

Citation Source

  • Scopus