Article ID Journal Published Year Pages File Type
1720920 Coastal Engineering 2012 19 Pages PDF
Abstract

To quantify the performance of several beach nourishment projects on three adjacent barrier islands located in west-central Florida, a total of 5200 beach and nearshore-profiles spaced at 300 m were surveyed monthly to bi-monthly from 2006 to 2010. Beach nourishment performance at annual temporal and kilometer spatial scales within the microtidal low-wave energy barrier island coast is most significantly influenced by the interruption of longshore sediment transport by complex tidal-inlet processes. The inlet processes directly influencing adjacent beach nourishment performance include longshore transport interruption resulting from divergence induced by wave refraction over an ebb-tidal shoal, flood-tidal currents along the beach, and total littoral blockage by structured inlets. Secondary factors controlling the nourishment performance include project length and width, shoreline orientation, and antecedent geology. A morphologic indicator of a large longshore transport gradient within the study area is the absence of a nearshore sandbar. These non-barred beaches are characterized by persistent shoreline erosion. The presence of a sandbar indicates the dominance of cross-shore processes, with bar migration in response to wave condition variations and a relatively stable shoreline. The entirety of a barrier island system should be considered when evaluating the performance of a nourishment.

► Interruption of longshore sediment transport influenced nourishment performance. ► Complex tidal-inlet processes significantly affected beach morphology changes. ► An indicator of a large longshore transport gradient is the absence of a bar. ► Bar migration and a relatively stable shoreline characterize the beach state.

Related Topics
Physical Sciences and Engineering Engineering Ocean Engineering
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