Impacts of Mississippi River diversions on salinity gradients in a deltaic Louisiana estuary: Ecological and management implications

Das, Anindita and Justic, Dubravko and Inoue, Masamichi and Hoda, Asif and Huang, Haosheng and Park, Dongho (2012) Impacts of Mississippi River diversions on salinity gradients in a deltaic Louisiana estuary: Ecological and management implications. Estuarine, Coastal and Shelf Science, 111 (1). pp. 17-26. ISSN (p) 0272-7714 (o) 1096-0015

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Abstract

Large-scale river diversions on the lower Mississippi River are considered to be an important component of wetland restoration efforts in coastal Louisiana. Diversions are used primarily for salinity control but increasingly proposed also as a major way to deliver sediments and nutrients to coastal wetlands impacted by the construction of flood control levees. We used a coupled hydrology–hydrodynamics model of the Barataria estuary, a site of the Davis Pond Diversion – the world's largest river diversion project, to examine salinity variations under different diversion discharge scenarios. Discharge scenarios were selected based on actual freshwater discharges in different years and management alternatives that included a scenario with several new diversions. The model results indicate that river diversions strongly affect salinities only in the middle section of the Barataria estuary. The upper parts of the estuary are fresh most of the time and so the excess fresh water from river diversions has only a minor impact on salinity in this region. Also, the Davis Pond diversion has little impact on salinities in the coastal section of the estuary because of strong marine influence in this area adjacent to the Gulf of Mexico. Interestingly, the predicted salinity differences between different model scenarios can be as high as 10 in some months and places. These differences can be biologically significant depending on the salinity tolerance of different species and could cause a shift in community composition within the affected region.

Item Type:	Article (Journal)
Additional Information:	6519/29152
Uncontrolled Keywords:	coastal ecosystems; estuaries; river diversions; salinity; Mississippi River; Gulf of Mexico
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Engineering > Department of Mechanical Engineering
Depositing User:	Nur' Aini Abu Bakar
Date Deposited:	16 Apr 2013 09:32
Last Modified:	16 Apr 2013 09:32
URI:	http://irep.iium.edu.my/id/eprint/29152

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