A PRELIMINARY STUDY USING REMOTE SENSING AND GIS TO DETERMINE THE EXTENT OF URBAN EXPANSION OF SOUTHERN JOHANNESBURG AND ITS EFFECT ON IRON AGE STONE-WALLED STRUCTURES

In the absence of relevant historical documents, stone-walled structures (SWS) are all the information we have about how precolonial societies were organised in what is now the southern Johannesburg region. Unfortunately, these SWS are threatened by rapid urbanisation and development. This research aims to estimate how many Iron Age SWS have been lost to urban development in southern Johannesburg during the last 80 years by using remote sensing techniques and GIS; and after that, how effective mitigation attempts have been in the area. Sadr (2017) estimated that for every 200 hectares of development, one SWS would be destroyed by development in southern Gauteng. The results from this study suggest a rate four times higher than that suggested by Sadr (2017). Aerial photographs and Google Earth images were analysed using ArcGIS 10.3 SAHRIS, and the University of the Witwatersrand archaeology archive was also consulted. The results indicate a decline in the number of Iron Age structures.