AGRASID: What has Changed

 
 
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 In AGRASID Version 1.0 polygons were unique to each township. This is no longer the case AGRASID Version 3.0. The township grid lines were dissolved so that soil landscapes polygons are now "whole" in that they are no longer dissected on the basis of the Alberta township grid. Each soil landscape polygon is now represented by one record in the polygon attribute file even though the soil landscape polygon may span multiple townships. The implication of this modification is that the number of polygons described in the polygon attribute files are reduced from approximately 65,000 to 28,000. This means that the derivation of value-added products from AGRASID is expedited. Other modifications include the correction of some identified errors in the database. Also the boundaries and descriptions of some Land System boundaries have been modified.

Descriptions of the soil landscape polygons as previously contained in the SL.dbf and MAS.dbf were consolidated within land systems. In version 1.0, a soil landscape polygon occurring in 2 or more townships would have 2 or more records in the SL.dbf and a multiple of records in the MAS.dbf depending upon the number of soils identified in each portion of the polygon. The consolidation of SL.dbf records was initially based on the corresponding MUNAME field within a Land System. As for the corresponding MAS.dbf records, the polygon portion having the most identified soils in the MAS.dbf have been subsequently assigned to the soil landscape polygon in this version of AGRASID.

The user may also notice that the outside boundaries of AGRASID Version 3.0 do not exactly match the 49th and 60th parallels of latitude and the 110th and 120th meridians of longitude.  This is because AGRASID was originally compiled on the Alberta township grid system, as found in the province's 1:20,000 scale base map. This means that AGRASID Version 3.0 will not necessarily follow the federal or provincial boundaries of the province.

The AGRASID Version 3.0 spatial data are being offered in two projections:

  • Ten Degree Transverse Mercator using the North American Datum 1983 (NAD83) and a false easting of 500,000 meters.
  • Geographic (Lattitude / Longitude Projection) using NAD83 as a datum.
    In addition the spatial data are available for download as a single seamless coverage, or by 1:250,000 scale NTS map block.
Agrasid is no longer distributed with a special viewer. Several excellent, free GIS data viewers are available through the internet. One is ArcExplorer® from ESRI.

The following data sets comprise AGRASID 3.0:

 
 
 
 
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For more information about the content of this document, contact David Spiess.
This document is maintained by Laura Thygesen.
This information published to the web on February 15, 2001.
Last Reviewed/Revised on February 24, 2015.