South Africa continues to experience rapid urbanization with 53.7 percent of the population living in urban areas in 1996 rising to 54.4 percent in 2001 and 67.7 percent in 2011.
It is therefore crucial to monitor urban growth spatially for sustainable development and environmental management. For this reason SANSA has developed methodologies to automatically extract human settlement data from satellite imagery.
Using 2006 and 2011 SPOT 5 imagery we assessed the spatial urban growth in the three metropolitan municipalities ie Cities of Johannesburg, Ekurhuleni and Tshwane, in Gauteng and compared their spatial growth with population growth.
The figure below shows spatial urban growth vs population growth within the three municipalities.
Understanding spatial urban growth and population growth is important during planning for services and conservation of natural resources.
These results can be used as input to derive Land Consumption Ratio (LCR) which if one of the indicators for progress made on SDG 11: Make cities and human settlements inclusive, safe, resilient and sustainable.