Location: South Africa

Contacts

• Johan Hammes (jhammes@mweb.co.za) terrain programmer in Pretoria
• Dr. Willem van Riet, (dfvriet@mweb.co.za) professor working on modelling park areas
  • Pilanesberg National Park

Government Data

• The main site is NGI - National Geospatial Information (CD:SM)
• Their pages for Digital Products and Prices give all the information.
• They have the whole of South Africa on a 400meter grid, with mountainous areas on a 200meter grid, and the 3 major metropolitan areas  on a 50 meter grid.  The dataset for the whole country is not yet available but is being added to regularly and is obtainable at regular intervals throughout the year.
• The data distributed at very low cost! (no more than a handling fee, roughly $3 per CD and postage of CDs)
• It includes raster images of the 1:50000 map series, and digital data in various formats.

Coordinate Systems

• Hartbeesthoek 94 - The New South Africa Datum has a great detailed description of the history, datums and projected coordinate systems (Lo17, etc.) [seems no longer reachable, but easily found in the wayback]

Other Imagery

• LandSat images are available from the Satellite Application Centre (part of CSIR) which is the local distributor of LandSat and SPOT for Sub Saharan Africa, a full LandSat image (about 180x180 km is about $2,000), and are not redistributable unless you rework them to some (legally unspecified) degree
• much better free LandSat source: simply use the GLCF ESDI

VTP Scenery

• as of March 2004, SRTM is also now a possibility, ~100m for free
  • April 2004, i assembled a scene with SRTM of the Cape area, with LandSat imagery from JPL WMS.  Oddly, i had to apply a ~6km offset (N-S) to get the datasets to align.  The results are pretty good, Enviro snapshot to the right.

Data Issues

• Report: Beware projection and registration issues.
• "If you buy a DEM and LandSat image orthorectified from the Satellite Application Center in South Africa (the local LandSat distributor), they will gladly give you 3 raster files with DEM data, each on its own projection, and a LandSat image, also on its own projection, that was rectified with roughly 300 to 500 GCP (ground control points).  They do not even realize this because their software automatically corrects for projections when they load data, so for them it look OK."
• "With less than 500 GCPs on a 200x200km area, in a lovely mountainous area, the orthorectification is often off by a few hundred meters.  Now that may be deemed "good" considering that you have a 32meter image and a 64meter height grid, after all, the error is less that 5 or 8 "pixels" (raster elements), but shadows completely miss mountains if you are off by that much."

Vegetation

• PlantZAfrica.com - Plants of southern Africa - incredible resource with plant pictures and maps of the numerous biological regions
• Protea Atlas Project
• Cape Nature Conservation has Nature Reserves sites which did host some free GIS data at one point, although as of August 2005 i cannot locate it.

Vegetation Billboard Images

The following thumbnails link to PNG images with alpha channels, for use as billboards.  They were taken by Johan Hammes at the Jonkershoek Nature Reserve near Stellenbosch (45 km east of Cape Town)

	Looks like common Calla Lilly, probably Zantedeschia aethiopica which is native to SA.  This is not technically a lily, so it shouldn't be confused with the lily in the genus Calla (Calla palustris, common name "wild calla")
	Calla Lilly, Zantedeschia aethiopica
	Calla Lilly, Zantedeschia aethiopica
	Definitely family Proteaceae, but looks like genus Leucadendron rather than Protea.  Common name unknown.  There are 7 Leucadendron species listed as occurring in Jonkershoek.
	genus Leucadendron
	genus Leucadendron
	genus Leucadendron
	probably Proteaceae, genus unknown
	purple flower, unidentified
	unidentified brush plant, component of mountain fynbos
	unidentified brush plant, component of mountain fynbos
	unidentified grass tuft
	unidentified grass tuft
	unidentified large tree
	large tree, looks like a pine (?) there are a lot of European pines growing in Jonkershoek, being managed by the SA forestry service
	unidentified large tree
	large bush, looks like Proteaceae