Geospatial approach for demarcating Jekyll Island State Park: Georgia barrier island Byungyun Yang a, * , Marguerite Madden a , Thomas R. Jordan a , H. Ken Cordell b a Center for Remote Sensing and Mapping Science (CRMS), Department of Geography, University of Georgia, Athens, GA 30602, USA b Forestry Sciences Laboratory, Office 238, 320 Green Street, Athens, GA 30602, USA article info Article history: Available online 10 October 2011 abstract Demarcation of upland and water/marsh boundary is a critical issue for management and protection of barrier island ecosystems. Most accurate, precise and confident approaches are required to resolve conflicts related to developable lands and conservation area. Barrier islands are especially prone to these conflicts because they are highly dynamic systems that are formed and reformed by rise and fall of tides and seal levels. In response, this research analyzes the demarcation of Jekyll Island State Park, Georgia, USA that is faced with management issues of balancing tourism and development with resource conservation. Questions addressed by this research include: (1) What are the standard sea levels used to demarcate barrier islands? (2) What are the best methods for most accurately estimating the total area of coastal barrier islands? (3) Do differences in tide elevations between back-barrier and ocean-front shorelines of barrier islands exist? Specifically, this research considers a number of environmental policies, regulations, and laws along with geospatial data such as aerial photography, Light Detection and Ranging (LiDAR) and GIS shapefiles. These data are used to define sea levels and outline of Jekyll Island State Park based on Mean High Water (MHW) levels with respect to 0.79-m, 0.85-m, 0.94-m, 1.00-m, and 1.49-m for the entire Jekyll Island State Park. The demarcations of different back-barrier marshland and ocean-front side of the island were also considered. Results indicate that the total area of Jekyll Island State Park may vary by as much as 3.31-km 2 or 7.2% depending on the jurisdictional sea level that is used to demarcate the island boundary. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Delineating coastal boundaries, and thereby demarcating the outline of barrier islands, is critical to resource managers, govern- ment administrators, developers and scientists specializing in coastal processes and impacts of climate change. Barrier islands are constantly changing, perpetually reformed by the conflicting processes of soil erosion and accretion and are forever affected by the ocean’s rise and fall (Hoyt, 1967). Despite a 400-year history of coastal mapping along the eastern shoreline of the United States, there is still no clear delineation of the coast and boundaries of barrier islands. This study is about the demarcation of Jekyll Island State Park off the Georgia coast (United States) which is essential to its legal management, development and conservation of an ecologically valuable national heritage (Fig. 1). The State-owned and managed island is rich in both cultural and natural resources. From around 2500 B.C, Native Americans inhabited Jekyll Island and Colonists (first European occupation by the Spanish) arrived there in the late sixteenth century. In 1733, James Oglethorpe established the English colony of Georgia at the location of the present-day city of Savannah. Jekyll had been named by General Oglethorpe to honor his friend, Sir Joseph Jekyll (McCash, 2005). Over the next many years, Jekyll Island was privately owned by wealth residents and after 1950, the Island became a part of the State Parks system of Georgia. Today, the Island is operated by the Jekyll Island State Park Authority (JIA) which oversees both development and preservation of natural and cultural resources (Hunter, 2008). It offers a diversity of habitats including marine, beach, dune, saltwater marsh, upland, and freshwater that support an estimated 845 plant species, 219 invertebrates, 215 fish, 41 amphibians, 66 reptiles, 346 birds, and 50 mammal species, as well as over 16-km of unspoiled beaches (Cabin Bluff Management, 2007). At present, Jekyll Island State Park is protected by the State of Georgia 1971 Act No. 427, and develop- ment is limited to 35 percent of the total island area. Once this * Corresponding author. Tel.: þ1 706 224 1546; fax: þ1 706 542 2388. E-mail addresses: yby@uga.edu, yys0910@gmail.com (B. Yang). Contents lists available at SciVerse ScienceDirect Ocean & Coastal Management journal homepage: www.elsevier.com/locate/ocecoaman 0964-5691/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ocecoaman.2011.09.011 Ocean & Coastal Management 55 (2012) 42e51