This dataset contains generalized landcover data for the Prairie Farm
Rehabilitation Administration (PFRA) agricultural extent of Alberta and
British Columbia. This dataset was subset into two shapefiles. The other
half of this dataset covers PFRA agricultural areas of Manitoba and Saskatchewan.
The Landcover Generalization process was undertaken to solve rendering
problems of the original vectorized landcover data due to its
unwieldy/overwhelming size. LANDSAT 7 imagery used in the process was
collected during the WGTPP. This landcover imagery has a 30 meter
resolution and is stored in over 1,100 vectorized 1:50,000 map sheet
tiles. The data requires over seven gigabytes of disc space. If the
user wishes to view a specific area, they must identify the 1:50,000 map
sheet, then browse to the desired mapsheet. Due to the great detail,
this vector product (l02 in GIS_LIB) becomes computationally impossible
on the desktop computer when multiple mapsheets are drawn. Spatial
analysis and modeling at provincial or western Canada extents are also
impossible in the mapsheet format.
The WGTPP Generalized Landcover is a seamless vector coverage, covering
the agricultural extent of Western Canada. The generalized vector
coverage is 124 MB in size, and requires roughly 60 times less space
than the mapsheet tiles, thus making it easily used with desktop GIS
applications. An algorithm was created using the processing tools of
the ArcINFO GRID module. A series of AMLs and digital rules have been
implemented in the event that new satellite imagery is acquired.