Alongshore Wave Energy and Sediment Transport on Southeastern Lake Huron, Ontario, Canada

Abstract

Variable alongshore wave energy and sediment transport along eroding cohesive bluffs on the Great Lakes are fundamental geomorphic processes leading to shoreline evolution. The WAVENRG model is utilised to determine wave refraction patterns, wave energy distribution, and alongshore sediment transport for a 40 kilometre section of the southeastern shoreline of Lake Huron, Ontario, Canada. In general, the southeastern Lake Huron shoreline appears to experience dominant southward transport of sediment, with periodic reversals in the lee of headlands leading to protected beaches. Increased erosion is noted at several sites as a function of limited sediment supply, sediment easily removed by wave action, and increased wave energy caused by steep near shore profiles allowing incoming waves to dissipate energy close to shore. South from Point Clark to Horizon View, increasing wave energy results in significant transport of the limited sediment supply creating severe long term erosion at Horizon View. Pocket beaches, reflecting periodic reversals of sediment transport as a function of south and southwest waves are noted at several sites. Beyond the Wright's Point headland, sediment deposition is noted with increasing wave energy toward s the Maitland River, indicating an increase in potential erosion. The study results have important implications for land use and planning initiatives with the identification of sites suitable for development, areas important for sediment supply, and the potential environmental impact from shoreline protection structures. The application of alongshore wave energy and sediment transport models, when combined with corresponding field evaluation studies, has the potential to assist in the development of shoreline management plans in areas characterised by the availability of near shore sediments.