Geospatial approach for demarcating Jekyll Island State Park: Georgia barrier island

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-km2 or 7.2% depending on the jurisdictional sea level that is used to demarcate the island boundary.