Introduction

National Geo-spatial Information (NGI)#

National Geo-spatial Information (NGI) is a component of the Department of Agriculture, Land Reform and Rural Development (DALRRD). The NGI provides land information for South Africa to its citizens. This includes topographic maps (vector as well as scanned map sheets), aerial photographs, contours, and other information like digital elevation models. This information can be obtained directly from the NGI, free of charge. We make a yearly run to the NGI's offices to obtain the latest data on a 14TB external hard drive. The data is then processed (e.g., reprojected) but remains substantially identical to the source data.

Contact details for the NGI are available on their website: ngi.dalrrd.gov.za. They also have an online portal where you can view and download their data here: cdngiportal.co.za/CDNGIPortal/.

We provide the following data based on what we obtain from the NGI, all strictly within the boundaries of South Africa:

Orthophotos

The NGI provides colour orthophotos for the entire SA. Othophotos flown before 2018 have a 50cm resolution, and newer orthophotos have a 25cm resolution. We reproject these images to WGS84 (geographic projection) in order to use them in a seamless map of the whole of SA. In the process, we reduce the size to around 7TB for the whole of SA, but this figure is growing rapidly as more of the country is updated with higher-resolution images, which take up 4× more space than the 50cm images.

It is important to note that the orthophotos are provided in a format that can only be used with PlanetGIS software. You can export small areas to GeoTIFF or georeferenced JPEG files, but if you need these images for use in other software, you should be using the original images, which you can obtain from the NGI at no charge.

It typically takes two to three years between the time that the NGI has the images flown and the time that they end up on our 8TB DataDrive. PlanetGIS has the capability to show Google, Bing and other images from the web. While these are much slower to use and use a lot of bandwidth, they are nearly always much more recent. The NGI images are usually of better quality, especially in terms of positional accuracy.

Contours

Chief Surveyor-General (CSG)#

The Chief Surveyor-General of South Africa is another component of the DALRRD. They provide cadastral boundaries for the whole of SA as well as survey diagrams, which are the legal documents upon which the electronic cadastral boundaries are based. Unfortunately, there is often a time lag or discrepancies between the diagrams and the boundaries captured in their GIS. The electronic version of the boundaries, therefore, must always be verified against survey diagrams and other sources before used in a manner for which accuracy is paramount.

The CSG charges a small fee to provide this information, but the information is free to be used and replicated in any form. The CSG can be contacted through their website at: csg.drdlr.gov.za

Please use the links on their website to submit feedback on any errors or omissions that you encounter in the data.

Survey diagrams

At some point in the future, we would like to provide the survey diagrams from our own server, linked directly to the relevant boundaries in the GIS. For the time being, you can do a search for diagrams on the CSGs website here: csg.drdlr.gov.za/esio/

GIS-based cadastral boundaries

We obtain shapefiles of all the provinces from the CSG, twice per year (usually in January and again in July). These are then imported into PlanetGIS, with a little bit of cleaning done by automated scripts. The actual coordinates of boundaries are never altered in any way.

We provide separate downloads for each province, in addition to one large download containing all the provinces and other information.

The CSG has an online property search portal at csggis.drdlr.gov.za/psv/. If you find that some boundaries in a PlanetGIS project are missing, outdated or incorrect, please use this link to check if those boundaries indeed exist at the source, and let us know. (If you don't see the boundaries here, don't expect to see them in Planet!).

Municipal Demarcation Board (MDB)#

We use the MDB's most recent boundaries for the following layers:

• Provinces
• District Municipalities
• Local Municipalities
• Wards

The MDB's website is here: demarcation.org.za

Stats SA#

We use StatsSA's main places and sub places layers, which are useful approximations for towns and suburbs. This is the only information from StatsSA that we provide, as there are generally restrictions on the use of their data.

StatsSA's website is here: www.statssa.gov.za

OpenStreetMap.org (OSM)#

OpenStreetMap is an open-source map of the entire world. All information contributed to this project is either collected by volunteers or donated without restriction. We provide an extract for South Africa and will do the same for other countries upon request.

The OpenStreetMap project can be found here: openstreetmap.org and anyone is free to contribute to the project.

The OSM map is refreshed twice a year, when we update the cadastral maps.