Date of Award

8-9-2014

Document Type

Open Access Dissertation

Department

Earth and Ocean Sciences

Sub-Department

Geology

First Advisor

Raymond Torres

Abstract

A range of studies shows that terrestrial and tidal channel dimensions increase in the downstream direction, transitioning seaward from a power function of discharge to an exponential function of distance from the coast. There are also an increasing number of studies on tidal hydrodynamics and sedimentology in channel reaches where river and tidal flows meet. However, there is a dearth of information on the channel form in fluvial-tidal transition, and therefore we have little understanding of what constitutes the fluvial-tidal transition channel, or channel reach. The Santee River in South Carolina is a gently sloping (average 10-5) coastal plain river that is fully terrestrial on one side and fully tidal on the other. This thesis presents analyses of a 65-km long profile and properties of sixty-five cross sections. Fluctuations in bed elevation increase toward the mouth. Also, from the terrestrial to tidal reaches, the channel width and area increase in the downstream direction. However, further downstream channel dimensions decrease over a 30-km reach before increasing exponentially. These observations and analyses lead us to propose that there exists a geomorphic expression of the fluvial-tidal transition, and it can be detected in other river studies that illustrate similar data.

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