An Investigation Into Using GIS In Network Planning In Rural Kwazulu-Natal

J B Barnard
Eskom Distribution, Eastern Region

ABSTRACT
The South African government has set a target of universal access to basic electricity by the year 2012. Eskom Distribution, in conjunction with local municipalities, is responsible for the outstanding electrification predominantly in rural areas. In KwaZulu-Natal, mountainous terrain and scattered settlement patterns of communities complicate the achievement of this goal. This study was aimed at showing how GIS can be used to design the shortest networks from the grid to an electrification area.

Designing the shortest path involved the use of four factors, these being roads, land cover, household positions and slope. Each layer was reclassified, ratings applied and a combined suitability raster created in order to successfully design the final path.

Extensive research into GIS practices worldwide, resolving of data quality issues, testing of points and weighting systems, and working together on making changes to age-old system structures and processes is needed before any of the recommendations resulting from this study can be effectively implemented.

INTRODUCTION
In order to determine the shortest path for an electricity network extension different network planning concerns need to be addressed. Currently network planners work manually, using maps and aerial photographs in order to find the optimal routes for network extensions. The more factors considered, the longer it would take to evaluate the maps and determine the shortest path manually. Electricity utilities and other route planners are turning more and more to using GIS as an effective alternative (Williams et al, 2003, Glasgow et al, 2004).

Using GIS a model can be created to overlay any number of requirements into one multi-criteria map which is created by reclassifying layers using relevant scores, which are then added together spatially. In the case of an electrical network, ideally the best route would run along the least slope, avoid forests, wetlands and other ecologically sensitive areas, be routed near to roads and avoid households, while running near densely populated areas in order to easily supply them with electricity. Planners, engineers and environmental scientists need work together to determine a standard points system for each layer in such a model (Glasgow et al, 2004).

CASE STUDY AREA
A case study site in the sub place area of Shayilanga / Kamlenze was chosen from a list of possible electrification areas to demonstrate how GIS can be applied in planning an extension from the nearest network to the schools within that area. The RAPS method of scoring was used to prioritise villages . This area scored the highest number of points out of 34 short-listed electrification areas which can easily be supplied electricity from the grid, due to the number and density of households, and the number of pupils at the two schools in the area. There are very few projects currently planned for the area as per the IDP for Ingwe Local Municipality

Figure 1: Case study site of Shayilanga/Kamlenze showing relief, schools, roads, rivers, and current Eskom MV networks and transformers