Sediment deposition and availability in the riparian wetlands of the Cape Fear River

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Devon Eulie (Creator)
Institution
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/
Advisor
Lynn Leonard

Abstract: Tidal riparian wetlands serve as buffers between upland areas and the adjacent river channel. The ability of these swamps and marshes to keep up with changes in sea level depends on a combination on several factors including: sediment availability, hydrologic regime, deposition rates, and below ground productivity, that control surface elevation. This study examines sediment availability, deposition, and elevation change across different types of tidal wetlands in the Lower Cape Fear River Estuary, North Carolina. The study used marsh and swamp sites as well as sites along two different stream types, black and brown-water, within the estuary. Marshes and wetlands along the brown-water river exhibited significantly greater and more variable deposition rates than swamps and wetlands located along the black-water river (0.720 ± 1.310 gm2day-1 and 0.710 ± 1.270 gm2day-1). The brown-water marsh site exhibited significantly greater rates of deposition than any of the other sites. Organic content of deposited material was highest at the black-water swamp site and lowest at the brown-water marsh site. Total suspended solids measured once a month over a single flood tide were highest at the black-water marsh (33.01 ± 43.54 mgL-1) and lowest at the black-water swamp (3.07 ± 10.62 mgL-1). Measurements of surface water flow during a single ebb tide at each site were examined along with the mean grain size of available material. Results showed vertical flow speed and grain size were the dominant controls on deposition in this system. Measurements of surface elevation at each wetland showed a loss of elevation at the marsh sites and very slight increases at the swamp sites. When compared to current rates of sea-level rise for the area, it appears that these wetlands are not able to maintain their elevation in the face of rising sea-level.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Keywords
Salt marsh ecology--North Carolina--Cape Fear River, Sediment control--North Carolina--Cape Fear River, Sediment transport--North Carolina--Cape Fear River, Sedimentation and deposition--North Carolina--Cape Fear River, Slackwater deposits--North Carolina--Cape Fear River, Wetlands--North Carolina
Subjects
Wetlands -- North Carolina
Sediment control -- North Carolina -- Cape Fear River
Salt marsh ecology -- North Carolina -- Cape Fear River
Sediment transport -- North Carolina -- Cape Fear River
Sedimentation and deposition -- North Carolina -- Cape Fear River
Slackwater deposits -- North Carolina -- Cape Fear River