Wetlands Restoration: An Experimental Method to Increase Sediment Supply in Subsidence-Dominated Environments

dc.acquisition-srcen_US
dc.call-noen_US
dc.contract-noen_US
dc.contributor.authorThomas, RCen_US
dc.contributor.authorMavens, TMen_US
dc.contributor.otherProceedings of the Eighth Biennial State of the Bay Symposium January 23-25, 2007en_US
dc.date.accessioned2010-02-15T16:46:54Z
dc.date.available2010-02-15T16:46:54Z
dc.date.issuedJan. 24, 2007en_US
dc.degreeen_US
dc.description[np]en_US
dc.description-otheren_US
dc.description.abstractThis project examines the environmental conditions which led to the loss of 90% of the natural salt marsh in Galveston Island State Park since 1930 and analyzes one potential method to reduce future loss. Available data and recent studies suggest that the primary factor responsible for the historic loss was the lack of sufficient sediment supply to keep up with relative sea level rise. The average rate of sediment accretion for the period from 1963 to 2006 was estimated to be approximately 0.25 cm/year based on bomb fallout nuclides. According to data published by the National Oceanic and Atmospheric Administration (2006), this rate is about 0.4 cm/year less than relative sea level rise of approximately 0.65 cm/year during the same period. GPS observations collected by the Harris-Galveston Coastal Subsidence District from 2002 to 2005 support the common theory that rates of relative sea level rise over the last century will continue in the future. The marsh restoration project constructed in 1999 at the Galveston Island State Park focused on reduction of wave induced erosion and direct replacement of marsh substrate through terracing, but did not address the potential for marsh lost to submergence. As an alternative to geotextile tubes or other more permanent breakwater methods, a submerged, sacrificial earthen berm constructed around the marsh is a possible approach to address ongoing submergence by increasing the available sediment supply. In addition, the berm could be designed to limit wave height in the marsh to reduce wave induced erosion while allowing partial transmission of waves to create a net transport of sediment from the berm into the marsh. The proposed design method involves iteratively adjusting the berm top width and elevation to maximize sediment transport from the berm into the marsh. A sediment transport model can then be developed to quantify the increased transport into the marsh and estimate a nourishment interval. The Galveston Island State Park marsh was used for demonstration purposes; however, the restoration concept and method of analysis is applicable to other marshes in Galveston Bay.en_US
dc.description.urien_US
dc.geo-codeGalveston Bayen_US
dc.geo-codeGalveston Island State Parken_US
dc.history1-21-09 kswen_US
dc.identifier.urihttp://hdl.handle.net/1969.3/18647
dc.latitudeen_US
dc.locationNot available in house - Please contact GBIC for assistanceen_US
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dc.notesen_US
dc.placeen_US
dc.publisherGalveston Bay Estuary Programen_US
dc.relation.ispartofseries10175.00en_US
dc.relation.urihttp://gbic.tamug.edu/gbeppubs/sobviii/sobviii_rpr.htm#Thomasen_US
dc.scaleen_US
dc.seriesen_US
dc.subjecthabitat lossen_US
dc.subjectsalt marshesen_US
dc.subjectwetlands restorationen_US
dc.titleWetlands Restoration: An Experimental Method to Increase Sediment Supply in Subsidence-Dominated Environmentsen_US
dc.typeCONFen_US
dc.universityen_US
dc.vol-issueen_US
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