How was or how is land area determined for the Census and Agcensus files?
Here is a description as to how land area is calculated for standard geographic areas.
The Census of Agriculture (CAR) Regions boundary file doesn’t have land area as an attribute; although CARs are composed of groups of adjacent Census divisions except for Saskatchewan. See note below:
Census agricultural region
Census agricultural regions (CARs) are composed of groups of adjacent census divisions.
In Saskatchewan, census agricultural regions are made up of groups of adjacent census consolidated subdivisions, but these groups do not necessarily respect census division boundaries.
Census consolidated subdivision
A census consolidated subdivision (CCS) is a group of adjacent census subdivisions. Generally, the smaller, more densely-populated census subdivisions (towns, villages, etc.) are combined with the surrounding, larger, more rural census subdivision, in order to create a geographic level between the census subdivision and the census division.