1995 Blowdown Metadata

New York State Department of Environmental Conservation, Division of Lands & Forests
GIS Coverage Documentation

Coverage Name: 1995blow.shp

Description: Storm Damage resulting from the 1995 Adirondack Derecho

Creator: GIS Section, Division of Lands & Forests, Bureau of Public Lands, Albany, NY.

Source of Information: Air photo interpretation performed by DEC Lands & Forests staff on over 125,000 acres of DEC region 5 & 6 forest lands

Projection: NAD83, Zone 18 UTM, meters

Methodology: Data was generated from 1:18000 scale color aerial photography captured by DEC Division of Aviation in July and August 1995. Interpretation of photography involved use of a sampling grid placed upon each photograph where each grid intersection depicted the point center of a 50 acre square parcel. Damage determination for each point ( representing the surrounding 50 acres ) was based upon change in the visible crown, consistently referenced by crown density scale. Each sample points damage value was recorded onto a 1:24000 scale paper map; Geographic position between photographic observation and corresponding map location maintained. Lines were generalized on the map around points of similar damage intensity, and thereafter digitized directly into an ARC/INFO coverage. Attribute labels were added along with the polygon datafield DAMAGE conveying the severity (L, M, H).

Data Manager: NYS DEC, 625 Broadway 5th Floor, Albany, NY 12233-4255, phone (518) 402-9453

Polygon Attributes:

L = Light = 0 - 30 % change in Dominant and Co-dominant crown
M = Moderate = 30 - 60 % change in Dominant and Co-dominant crown
H = Heavy = 60 - 100 % change in Dominant and Co-dominant crown