This geodatabase represents a landcover mapping geographic infromation dataset for Glacier Bay National Park in Alaska. The Alaska Landcover Mapping Program is funded through the Inventory portion of the National Park Service (NPS) Inventory and Monitoring Program (I&M) and has as its goal providing basic vegetation information on a park-wide basis for all National Parks in Alaska. Landcover mapping is intended to provide data that are useful for the design and implementation of other I&M Programs as well as facilitate general resource management decisions within parks. The Glacier Bay landcover mapping program began with an initial project under separate agreement that provided for manual photointerpretation of landcover types within the Park using color infrared (CIR) photography. This photointerpretation was captured as delineations on mylars that overlay the CIR photography. The imagery was procured from air photo flying missions conducted on 07-27-1996 and 07-28-1996. The scale of the final hardcopy photo print product was 1:65,000. Digital imagery was produced by Saint Mary's University of Minnesota GeoSpatial Services by scanning the hardcopy photo transpercy on an Epson Expression 1640 XL flatbed scanner at a resolution of 1200 DPI. The resulting scans were resampled using nearest neighbour resampling techniques to a 16 bit, multi-band TIFF format image file. The scanned images were then georeferenced and orthorectifed using black and white DOQQ imagery and digital elevation data provided by the National Park Service. After the images and mylar overlays were orthorectified, the polygon data representing the park landcover was cleaned up (leading lines removed, gaps closed, lines extended etc.) and converted from raster to vector format using ArcScan software on a photo by photo basis. The linework resulting from each photo was positionally validated against Glacier Bay DOQQ's and then edgematched with adjacent photos in order to assemble landcover data for the entire Park boundary. Finally, the polygons were attributed with the appropriate landcover code using an attribute table provided by the NPS Inventory and Mapping Program. For assorted reasons, in some instances the map attribute differs from that on the mylar.
