Interaction of Tidal and Fluvial Processes in the Transition Zone of the Santee River, SC, USA
- 356 Downloads
This study was conducted in the freshwater reach of the Santee River approximately 55 ± 4 km from the mouth, a transition zone from a fluvial to an estuarine tidal regime. The dataset comprises bathymetric surveys, current profile and bottom pressure measurements at two locations, and time series of discharge. Our data indicate that the transition zone is characterized by strong tidal dissipation and distinctive channel geometry. Tidal dissipation is evident in the rapid decrease of the M2 amplitude to the mean along-channel velocity ratio from 2.1 to 0.9 over a ∼6-km distance. Channel cross-sectional area in the transition zone converges at a higher rate than both upstream and downstream while channel depth reveals threefold variations in the form of adjacent shoals and deeps. We hypothesize that the enhanced tidal dissipation is at the same time a cause and a result of strongly convergent bathymetry in the transition zone.
KeywordsRiver discharge Tidal dissipation Overtide Logarithmic layer Channel convergence
The authors are thankful to anonymous reviewers for their stimulating comments and suggestions. This study was supported by NSF grant EAR-1053299. AY was partially supported by the University of South Carolina start-up funds.
- Lapine, L.A., Wellslager, M.J. 2007. GPS + GLONASS for precision, SC’s GNSS virtual reference network. Inside GNSS, July/August issue, pp. 50–57.Google Scholar
- Pritchard, D.W. 1956. The dynamic structure of a coastal plain estuary. Journal of Marine Research 15: 33–42.Google Scholar
- Pritchard, D.W. 1967. What is an estuary: Physical viewpoint. In Estuaries, ed. G.H. Lauf, 3–5. Washington: A.A.A.S. Publication No. 83.Google Scholar
- Schlichting, H. 1960. Boundary layer theory, 2nd ed. New York: McGraw-Hill.Google Scholar