Page 21 - Interp Book

corridors were 30 m wide and were applied to portions of polygons derived from
image objects.
3. A %slope designation generated from 10 m digital elevation models (DEMs; see
USGS National Elevation Dataset, http://ned.usgs.gov/). In most regions, land
cover on slopes greater than 20% were assigned to slope Ecological Mapping
Systems or Mapping Subsystems, separate from flatter areas.

In addition, transportation corridors were ‘burned in’ to the final map by reference to
center lines from US Census TIGER data (see http://www.census.gov/geo/maps-
data/data/tiger.html).

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