True color orthophoto with vegatation type class coded polygons.

LIDAR derived vegetation height classes with vegatation type coded poylgons. Blue = 2-15 feet, orange = 30-60 feet, pink > 60 feet.

Eastern Neck NWR cover type map.

In September 2004 Chesapeake Marshlands National Wildlife Refuge Complex contracted with Woolpert, Inc. of Portsmouth, VA to acquire aerial photographs and with James W. Sewell Company of Old Town, ME to produce a vegetation map of the refuge complex and surrounding lands. The mapped areas include Blackwater National Wildlife Refuge and adjacent lands (54,073 acres), Eastern Neck National Wildlife Refuge (2,094 acres), seven Chesapeake Bay islands (14,189 acres), and a portion of the Nanticoke River watershed (24,052 acres).

Aerial photography was acquired on two occasions to maximize detection of differences of two major classes of vegetation. In order to enhance differentiation of canopy species Nanticoke, Eastern Neck and Blackwater were photographed in May 2005 using color infrared film to capture the forested lands at leaf blush. In August 2005 the entire 94,408 acre project area was photographed with true color film to provide images for the classification of marsh species and species groups. Products received include 1:12,000 scale prints and triangulated, DEM processed, and ortho-rectified digital photography for the May and the August flights. The color film was scanned to produce a mosaic of orthophotos with a 0.25 meter pixel resolution.

James W. Sewall Company used full stereo coverage aerial photography supplied by Woolpert to produce vegetation maps. In consultation with NatureServe, the National Vegetation Classification System was used in combination with Ecological Systems which were developed to enhance the usability of the final product. There are three types of interpretation coding for the project: Forests, Non-Forested Wetlands, and Landuse codes. Forests have a minimum mapping unit of 1 hectare, while non-forested wetlands and landuse types have a minimum mapping unit of 0.5 hectares.

LIDAR data, provided by the state of Maryland, were processed by Sewall by extracting the data from text files and creating ArcGIS grids with 2-meter cell size. The resulting grid tiles were merged to produce individual data sets for bare earth and maximum first return. The grid files were processed to produce three grid data sets representing heights.

Delivered products include: printed and geo-referenced digital aerial images in color infrared (Nanticoke, Blackwater, and Eastern Neck) and true color (entire project area); vegetation cover types provided in ArcGIS project format, including vegetation height and bare ground elevations; and International Ecological Classification Standards for Chesapeake Marshlands National Wildlife Refuge Complex and Chesapeake marshes (NatureServe). The total project cost was $309,647 for mapping of 94,408 acres ($3.28/acre).