Digital Elevation Monitoring for Eastern Neck Restoration

Site:

Eastern Neck National Wildlife Refuge, MD

Purpose(s):

(1) Monitor vegetation growth over time to gauge success of the project
(2) Demonstrate the importance of Digital Elevation Monitoring (DEM) as a restoration tool

Summary:

In the 1980s the U.S. Army Corps built two cells of rock wall structures along the west side of Eastern Neck Island to prevent erosion, which was occurring at an annual rate of five to twenty five feet. Though these barriers halted erosion, plant life behind the barriers was obliterated by deposition of sand which smothered or washed away vegetation. Additionally the area right behind the barriers was still losing elevation. In an effort to maintain the elevation of the area, the natural fetch that deposits sand within the cell were occasionally supplemented with dredge material from the surrounding shipping areas. After the first deposits in 1999-2000, the National Aquarium in Baltimore established non-permanent transects running perpendicular to the rock wall and beach to help generate a digital elevation model (DEM). The National Aquarium in Baltimore continued restoring plant life in the north and south cell. NGS made a DEM of the south cell and bottom half of the north cell in 2004, 2007, and 2008, and continued to collect GPS data along the transects. NGS also used an experimental program which incorporates the DEM, tides, and plant species into its analysis to help the National Aquarium in Baltimore determine where to plant different species for optimum growth and survival.

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