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

METHODOLOGY
Four of the most important factors were used and these were roads, land cover, household positions, and slope (Eskom, 2000):

Roads
Roads are ideal routes along which to plan electricity networks as they are usually already leveled, at a reasonable gradient, cleared of vegetation and networks next to roads are convenient for line patrols, planned maintenance and emergency work. A distance allocation raster was created and reclassified according to distance from the road.

Land Cover
Land cover data contains areas demarcated as different types of cultivated land, degraded land, grasslands, mines, scrubland, forests, wetlands and others. The land cover data was converted to raster and reclassified as shown in figure 2.

Household Positions
A raster was created from the household positions and points allocated to ensure that networks run near to existing households.

Slope
A TIN was created from 20 metre DEM points and a slope raster derived. Slopes were allocated points according to the steepness of the slope.

Figure 2: Study sites: Determining shortest path from network to school

Combined Suitability Raster
The layers were then overlaid and the values for corresponding pixels added together. Where the resultant combined suitability raster has pixels with a combined rating equal or near to zero, this will identify the best path for an extension or new network.

Figure 3: Study site: Shayilanga / Kamlenze: Reclassification of straight line distance raster created from roads

Figure 4: Study site: Shayilanga / Kamlenze: Reclassification of raster created from land cover

Figure 5: Study site: Shayilanga / Kamlenze: Reclassification of straight line distance raster created from households

Figure 6: Study site: Shayilanga / Kamlenze: Reclassification of raster created from slope

Figure 7: Study site: Shayalinga / Kamlenze: Combined suitability raster