Historical shoreline and bathymetric survey data were compiled for the barrier islands and passes fronting Mississippi Sound to develop a regional sediment budget spanning a 90-year period. Net littoral sand transport along the islands and passes is primarily unidirectional (east-to-west). Beach erosion along the east side of each island and sand spit deposition to the west result in an average sand flux of about 430,000 cy/yr throughout the barrier island system. Dog Keys Pass, located updrift of East Ship Island, is the only inlet that is a net sediment sink. It also is the widest pass in the system and has two active channels and ebb shoals. As such, a deficit of sand exists along East Ship Island. Littoral sand transport decreases rapidly on West Ship Island, where exchange of sand between islands terminates because of wave sheltering from shoals and islands of the old St. Bernard delta complex, Louisiana.Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it Historical shoreline and bathymetric survey data were compiled for the barrier islands and passes fronting Mississippi Sound to develop a regional sediment budget spanning a 90-year period. Net littoral sand transport along the islands and passes is primarily unidirectional (east-to-west). Beach erosion along the east side of each island and sand spit deposition to the west result in an average sand flux of about 430,000 cy/yr throughout the barrier island system. Dog Keys Pass, located updrift of East Ship Island, is the only inlet that is a net sediment sink. It also is the widest pass in the system and has two active channels and ebb shoals. As such, a deficit of sand exists along East Ship Island. Littoral sand transport decreases rapidly on West Ship Island, where exchange of sand between islands terminates because of wave sheltering from shoals and islands of the old St. Bernard delta complex, Louisiana.
to develop a sediment budget for assessing net changes in seafloor configuration relative to wave and current processes and engineering activities. Although the immediate area of interest is Mobile Bay proper, sediment contributions from the Mobile Bay watershed and shorelines adjacent to the Bay, and sediment exchange with eastern Mississippi Sound through Pass aux Herons and the northern Gulf of Mexico through Mobile Pass, influence the degree to which sediment is deposited within the Bay and redistributed under storm and normal conditions. Documented seafloor changes were used to quantify the flux of sediment within the Bay relative to contributions from the fluvial watershed, adjacent shoreline environments, and from the northern Gulf of Mexico through Mobile Pass. Study results have been used for environmental management purposes related to channel dredging and disposal practice, and water quality and living resources, within the Bay. BACKGROUND: Mobile Bay estuary is a bell-shaped, submerged river valley system approximately 50 kilometers (km) (31 miles [mi]) long between the estuary mouth at Mobile Pass and the terminus of the Mobile-Tensaw River system, 37 km (23 mi) wide between Mississippi Sound and the eastern shore of Bon Secour Bay, and approximately 16 km (10 mi) wide where it meets the Mobile-Tensaw River Delta (Figure 1) (Hummell 1996). The Bay receives water and sediment from the Mobile-Tensaw River system, the nation's fourth largest river system relative to discharge and sixth largest in terms of total drainage area (Isphording and Flowers 1987). The bay encompasses approximately 1,070 km 2 (413 mi 2) of open water (Isphording et al. 1996) and has an average depth of approximately 3 meters (m) (9.7 feet [ft]) at mean high water (Chermock et al. 1974). The entrance, between Mobile Point on the western end of Fort Morgan Peninsula and Pelican Point on the eastern end of Dauphin Island, is an extensive natural inlet with channel depths in excess of 18 m (60 ft). It is commonly referred to as Mobile Pass and is the primary point of access between Mobile Bay (via the north-south Mobile Ship Channel) and the Gulf of Mexico. The entrance is approximately 5 km (3 mi) wide. Fort Morgan Peninsula forms the southeastern terminus of Mobile Bay in southern Baldwin County and consists of an extensive beach backed by parallel dunes and numerous sub-parallel beach ridges, formed as a result of net longshore sediment transport processes (Bearden and Hummell 1990; Stone et al. 1992). The east-west Intracoastal Waterway intersects the Mobile Ship Channel just inside the entrance to Mobile Bay (Figure 1). The waterway connects Mississippi Sound with Mobile Bay via Pass aux Herons on the west and traverses east to Perdido Bay via Bon Secour Bay.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.