Ebb-Tidal Delta Response to Jetty Construction at Three South Carolina Inlets
Many studies have described effects of jetties on littoral sediment transport, inlet channel 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 MurrelTs Inlet and Little River Inlet.
Confinement of flow by jetty construction has resulted in “tidal flow abandonment” of natural main ebb channels, swash platforms, and marginal flood channels, 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 Little 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 Little River inlets, onshore welding of ebb-tidal shoals has not occurred.
KeywordsSediment Transport Tidal Inlet Tidal Prism River Inlet Army Engineer Waterway Experiment Station
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- Barwis, J.H., 1976. Annotated bibliography on the geologic, hydraulic, and engineering aspects of tidal inlets. GITI Rept. 4, US Army Engineer Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS, 333 pp.Google Scholar
- Barwis, J.H., Perry, F.C. and LaGarde, V.E., 1977. Computer-aided photo studies of inlet stability. In: Coastal Sediments 77, Fifth Symposium of the Waterway, Port, Coastal and Ocean Division of the ASCE, Charleston, S.C., p. 1057–1072.Google Scholar
- Brown, P.J., 1977. Variations in South Carolina coastal morphology. In: Nummedal, D. (ed.), Beaches and Barriers of the Central South Carolina Coast, field trip guidebook, Dept. of Geol., Univ. S.C., p. 11–24.Google Scholar
- Davies, J.L., 1964. A morphogenic approach to world shorelines. In: Zeit, für Geomorph., 8:127–142.Google Scholar
- Dean, R.G. and Walton, T.L. Jr., 1973. Sediment transport processes in the vicinity of inlets with special reference to sand trapping. In: Proc. 2nd Int. Estuarine Research Conf., Colombia, S.C., p.129–150.Google Scholar
- Douglass, S.L., 1987. Coastal response to navigation structures at Murrell’s Inlet, South Carolina, Tech. Rept. 87–2. US Army Engineer Waterways Experiment Station, Coastal Engineering Research Center, Yicksburg, MS, 244 pp.Google Scholar
- Fico, C, 1977. Wave refraction studies on the South Carolina coast, In: Nummedal, D. (ed.), Beaches and Barriers of the Central South Carolina Coast, field trip guidebook, Dept. of Geol., Univ. S. C, p. 1–10.Google Scholar
- Fitzgerald, D.M., Hubbard, D.K. and Nummedal, D., 1978. Shoreline changes associated with tidal inlets along the South Carolina coast. In: Coastal Zone 78, Symposium on Technical, Environmental, Socioeconomic, and Regulatory Aspects of C.Z.M., ASCE, San Francisco, p. 1973–1974.Google Scholar
- Hansen, M., Pope, J., Rosati, J.D. and Knowles, S.C., 1988. Evaluation of the Impact of Charleston Harbor Jetties on Folly Island, South Carolina. Tech. Rept. 88- .US Army Engineer Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS (in press).Google Scholar
- Hayes, M.O., 1979. Barrier island morphology as a function of tide and wave regime. In: Leatherman, S.P. (ed.), Barrier Islands, from the Gulf of St. Lawrence to the Gulf of Mexico, Academic Press, NY, p. 1–27.Google Scholar
- Hubbard, D.K., 1975. Morphology and hydrodynamics of the Merrimack River ebb-tidal delta. In: Cronin, L.E. (ed.), Estuarine Research, Vol II, Academic Press, p. 253–266.Google Scholar
- Hubbard, D.K., Barwis, J.H. and Nummedal, D., 1977. Sediment transport in four South Carolina inlets. In: Coastal Sediments 77, 5th Symp. of the Waterway, Port, Coastal and Ocean Div. of the ASCE, Charleston, S.C., p. 734–753.Google Scholar
- Jensen, R.E., 1983. Atlantic coast hindcast, shallow-water, significant wave information. WIS Rept. 9, US Army Engineer Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS.Google Scholar
- Partheniades, E. and Purpura, J.A., 1972. Coastline changes near a tidal inlet. In: Conf. Coast. Engr., 13th Proc., p. 843–864.Google Scholar
- Perry, F.C. Jr, Seabergh, W.C. and Lane, E.F., 1978. Improvements for Murrell’s Inlet, South Carolina. Tech. Rept. H-78–4, US Army Engineer Waterways Experiment Station, Hydraulics Laboratory, Vicksburg, MS, 69 pp.Google Scholar
- Seabergh, W.C, 1983. Weir Jetty Performance: Hydraulic and Sedimentary Considerations. Tech. Rept. HL-83–5, US Army Engineer Waterways Experiment Station, Hydraulics Laboratory, Vicksburg, MS, 106 pp.Google Scholar
- Seabergh, W.C. and Lane, E.F., 1977. Improvements for Little River Inlet, South Carolina. Tech. Rept. H-77–21, US Army Engineer Waterways Experiment Station, Hydraulics Laboratory, Vicksburg, MS, 83 pp.Google Scholar
- Stapor, F.W. Jr. and May, J.P., 1987. Sediment transport and ebb-tidal delta development at Charleston Harbor entrance, South Carolina. In: Proc. of Coastal Sediments ′87, ASCE, 16 pp.Google Scholar
- Zarillo, G.A., Ward, L.G. and Hayes, M.O., 1983. Historical atlas of tidal inlet changes, South Carolina, S.C. Sea Grant Consortium, Draft Rept.Google Scholar