Effects of Density and Bathymetry on Salinity Transport in the Savannah Estuary: Port Wentworth to I-95
Term of Award
Master of Science in Applied Engineering (M.S.A.E.)
Document Type and Release Option
Thesis (restricted to Georgia Southern)
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 License.
Department of Mechanical Engineering
Committee Member 1
Committee Member 2
The Savannah Estuary is a unique system which sits at the termination point of the Savannah River and flows into the mouth of the Atlantic Ocean. The estuary is subject to semi-diurnal tides and has been classified as a partially mixed estuary to the south and well-mixed estuary to the north. Additionally, the estuary is subject to low freshwater flow from Clyo, Georgia, and its salinity is vertically uniform, gradually decreasing further up the estuary. The Savannah Harbor Expansion Project (SHEP) will deepen the lower portion of the estuary from its current depth of 42’ to a new depth of 48’. This poses a potential risk to the fresh water intake of the city, located at Abercorn Creek, two miles from the confluence of Abercorn Creek and the Savannah River. Salinity-levels recorded daily at several US Geological Survey (USGS) gauging stations along the Savannah Estuary showed a gradual decrease in salinity throughout the study area as expected. However, a sharp non-gradual decrease in salinity was noticed between Port Went Worth, located near GA 25, and the gauging station at the I-95 bridge. Field data collected during this study showed a 188% decrease in salinity from Port Wentworth to I-95. A review of bathymetry data from USACE showed that there were in fact deep horizontal channels located throughout that stretch of the estuary. Results suggest that the estuary’s unique channel geometries acted as a salinity trap preventing the advection of chlorides in the salt water further north and finally affecting salinity profiles along this section of the estuary. From an engineering-management perspective this natural phenomenon can be exploited to prevent the advection of salinity further north into the municipal fresh water intake.
Riggs, Bryan N. 2017 "Effects of Density and Bathymetry on Salinity Transport in the Savannah Estuary: Port Wentworth to I-95". Georgia Southern University
Research Data and Supplementary Material