Rollup SLC Components

Overview

This form will creates an ARC/INFO AML that will summarize SLC components to higher levels in the national ecological framework (i.e. ecodistricts, ecoregions, ecoprovinces, or ecozones). 

Background

In order to summarize items that apply to entire SLC polygons, such as those items found in the LAT, it is simply a matter of creating a summary table using the summary button in ARCVIEW, or the Frequency command in ARC/INFO. Summarizing the contents of attributes that apply to portions of SLC polygons, such as those identified in the Component Table, is a little more problematic.

 Components in the SLC Component Table are defined as a percentage of the land area of the polygon. In order to summarize these attributes at the ecodistrict, ecoregion, or ecozone level, the percentage occurrence must be prorated by the land area of the respective polygons.

 Since the SLC databases are a generalized product, the summaries produced by this program are also generalized. After the summary is created, percentages of less than 1 are dropped, and the percentages of the remaining components are recalculated to total 100%.

This latest version produces correct rollups for version 2.2 in Alberta, and includes the ecoprovince level of the hierarchy.

Create the AML

SLC coverage name:
SLC Component Table name:  Not {cover name}.{item} !
Item to summarize:
rollup level:	ECODISTRICT  ECOREGION  ECOPROVINCE  ECOZONE

Source: Peter Schut
Contact: Head, CanSIS