Ebb-Tidal Delta Response to Jetty Construction at Three South Carolina Inlets

  1. David G. Aubrey and
  2. Lee Weishar
  1. Mark Hansen and
  2. Stephen C. Knowles

Published Online: 23 MAR 2013

DOI: 10.1029/LN029p0364

Hydrodynamics and Sediment Dynamics of Tidal Inlets

Hydrodynamics and Sediment Dynamics of Tidal Inlets

How to Cite

Hansen, M. and Knowles, S. C. (1988) Ebb-Tidal Delta Response to Jetty Construction at Three South Carolina Inlets, in Hydrodynamics and Sediment Dynamics of Tidal Inlets (eds D. G. Aubrey and L. Weishar), Springer-Verlag, New York. doi: 10.1029/LN029p0364

Publication History

  1. Published Online: 23 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9783540968887

Online ISBN: 9781118669242

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Keywords:

  • Charleston Harbor inlet;
  • Ebb-tidal deltas;
  • Jetty design and construction;
  • Little River Inlet;
  • Murrell's Inlet;
  • Tidal inlet stabilization

Summary

Many studies have described effects of jetties on littoral sediment transport, inletchannel configuration, and effects on adjacent beaches. Effects of jetty construction on ebb-tidal delta morphology are less documented. This report examines such effects at three South Carolina inlets. Historical bathymetric surveys were digitized for the Charleston Harbor ebb-tidal delta areas, whereas air-photos were used qualitatively to map morphologic changes that occurred during and following construction of jetties at Murrell's Inlet and Little River Inlet.

Confinement of flow by jetty construction has resulted in “tidal flowabandonment” of natural main ebb channels, swash platforms, and marginal floodchannels, resulting in effects similar to natural ebb-tidal delta breaching. Lack of significant tidal flow caused wave dominance of ebb-tidal delta areas adjacent to the jetties, resulting in landward sediment transport.

At Murrell's and Little River inlets, sub-aerial shoaling and beach ridge welding just offshore of southwest beaches created protected lagoon areas. Based on short term analysis (< 10 years), typical ebb-tidal delta morphology has been modified greatly at Murrell's and Litde River inlets. New ebb-tidal delta growth has been occurring seaward of the jetties at Murrell's Inlet. Future monitoring will reveal if similar seaward transport is occurring at Little River Inlet.

Similar responses of the ebb-tidal delta have occurred at Charleston Harbor,however, the response time has been longer and the changes less dramatic. In contrast to Murrell's and Litde River inlets, onshore welding of ebb-tidal shoals has not occurred.