In order to practically achieve this, the eligible voting electorate (approximately 22 million voters) had to be located (or placed) geographically so that a person's name can only appear once on the voters' roll. The Electoral Act therefore provides for the creation of voting districts where one voting district has one voting station and represents one segment of the national voters' roll.

Realising the impact of this on the electoral process, the Electoral Steering Committee initiated a process in February 1997 to create a continuous spatial database for the entire country in conjunction with the Department of Land Affairs and Statistics SA. In June 1997, the various project teams commenced the collection, creation, assimilation and quality checking of the geographic data sets with respect to:

* Topographical data (1:50 000 map series with road, rivers, contours etc).

* Rural and urban cadastral data (eg erven, farm boundaries, streets), approximately 7 million land parcels; and

* Census enumerator areas, approximately 91 000 units.

Final delivery to the IEC of the first continuous geographical data set for the country took place a year later in early June 1998.

Technology applied

The IEC established what is probably one of the largest and most complex GIS installation sites in South Africa. A total of nine A0 Hewlett-Packard 2500 plotters were used for the production of A0 maps (making it one of the largest HP plotter sites in the world at the time), together with a number of Canon copiers used for A3 colour printing, Hewlett-Packard high-end computer workstations (256 Mb of RAM, 233-400 MHz PII processors and 9 GB fixed disks), a high-speed Ethernet network (100 Mbps) and powerful servers (512 MB RAM, 4 x 200 MHz Pentium pro processors and 270 Gb fixed disk storage space) enabled them to handle approximately 200 GB of geographical information on an SQL database. A record number of 46 million database transactions were processed/captured in a single 24 h period directly preceding the first registration weekend.

The nine large-format HP-A0 plotters operated concurrently with high-speed colour printers and Zeh Plotting Software (ZEH) to produce 15 000 colour A0 maps.

One of the challenges that the IEC faced during this process was not only the compilation of, but also the physical plotting of the large number of A0 maps within a limited timeframe. Due to the large datasets generated within the GIS environment, several problems were experienced:

* Processing on the devices took up to 45 minutes, wasting valuable plotting time.

* Some files were too large in file size to be processed and plotted on the devices and aborted after processing for a long time.

* Plots were incomplete due to memory limitations on the devices.

At this time Advanced Imaging Solutions (AIS), the local sole distributors for Zeh Plotting Software were called in to address these issues and to ensure optimum plotting performance and utilisation of existing resources.

The solution

A multiprocess Zeh Plot server was installed which processed plot files (already compiled on the GIS system) in a matter of minutes and passed native RTL output files to the plotters, enabling maximum throughput and utilisation of these devices.

The Zeh plotting software is independent of memory on output devices, and is application and device independent and runs on most operating systems.

The A0 maps were used to provide an overview of delimited voting districts in each of the then 843 municipalities and, together with the A3 detail maps, obtain input and verification of the delimitation from the local party liaison structures.

The geographic database was also utilised for the production of spatial management reporting maps, inter alia, monitoring the registration progress, pinpointing potential security issues and identifying telecommunications and infrastructure needs in time to take corrective measures.

The GIS database, which was compiled for and during the delimitation process, has now become a national asset, which can be utilised by various state departments and private organisations for spatial planning.

Advanced Imaging Solutions

(012) 672 5783