Optimus Template

The Integrated Digital Electoral Atlas (INDEA) provides a comprehensive and up-to-date network of roads and other basemap features, along with electoral boundaries, for the entire Province of BC. The primary aim in the development of the INDEA was to provide Elections BC (EBC) with an integrated electronic dataset on which to base its management of Provincial elections. Special functionality in the INDEA has been provided to support EBC's needs for maintenance of Electoral District (ED) and Voter Area (VA) boundaries, generation of a Street Index, assignment of voters to the appropriate ED and VA on the basis of geocoding their addresses and map production. The first release of the INDEA was produced by BCS in 1999, and further enhancements of data and functionality are currently underway.

The backbone of the INDEA is an extensive set of road segments associated with address ranges. Each road segment can contain values for a wide variety of attributes, such as name, aliases, left/right address ranges and number of lanes. Of these, the most important for EBC's purposes are the name and address ranges, since these allow geocoding of the addresses in their Voter Register. The aim of the type of geocoding required by EBC is for the INDEA to provide the correct ED and VA corresponding to any address in the Province. To support this aim, considerable effort has been devoted to making the assignment of address ranges as complete, accurate and current as possible.

Several complete and consistent boundary sets (i.e., the ED and VA boundaries at a particular time) are also maintained in the INDEA as separate coverages. Additional coverages are also used to store an integrated set of municipal, Regional District, and Indian reserve boundaries, as well as a reference set of community boundaries. These coverages are regularly reconciled with the roads layer to ensure that all crossings are noded, so that the administrative region (ED, VA, municipality, etc.) associated with any side of any road segment can be unambiguously determined. In addition, the boundary data have been rectified with any features (e.g., roads and hydrography) in the basemap layers with which they are meant to correspond.

Many other types of data are also included in the INDEA. These include:

• point features, including address points and locations of small communities;
• line features, including coastlines, rivers, streams, railways and transmission lines;
• areal features, including lakes, islands, parks, schools, colleges, universities, hospitals, airports and Indian reserves.

All these data types can be associated with appropriate attributes.  They provide a wealth of background and reference data for the INDEA basemap, and for specific EBC applications such as VA boundary delineation.

The INDEA is housed in an IBM Informix Dynamic Server database.  This object-relational database management system (ORDBMS) provides for tight integration between the spatial and attribute components of the data, while allowing the enforcement of rules to ensure that the data conform to high standards of quality, reliability and consistency.  Sophisticated querying and spatial analysis of the data is supported by an extensive set of functions developed by BCS, collectively known as TerrainWorks®.

The INDEA project has also required the development of extensive software applications to operate on this data and allow for its updating and maintenance.  These utilities provide the capability to perform operations such as:

• Geocoding.  Address geocoding takes a street address as input and returns the ED and VA corresponding to that address. Point geocoding returns the estimated geographic position corresponding to the input address.
• Export.  Selected contents of the INDEA (i.e., particular features within a region of interest) can be specified and extracted into a shapefile.
• Time travel.  The INDEA supports versioning; i.e., as a particular feature is replaced or updated, the original feature is retired, but is still maintained in the database.  This allows rollback to obtain that version of the data which was in effect at a previous point in time.
• Data maintenance.  The INDEA Data Manager (IDM) provides an environment to view, analyze, edit and update ED and VA boundaries, municipal boundaries, roads and background features.
• Map production.  An extensive facility has been provided for EBC to use the INDEA data to produce several map series.  This facility provides tools for road density analysis, inset generation and management, automated labeling, generation of required tables and border component generation and placement.

Example Voter Area Map (pdf)