Abstract
The City of Ekurhuleni has great economic potential, also attributed to the recent Aerotropolis strategy, and has over the years experienced large amounts of migration into the city. Subsequently, it is equally challenged with insufficient provision of housing to accommodate low-income persons. The city is similarly home to 119 informal settlements with a population of 160 000 persons that are in the process of being housed and others still waiting to be housed in sustainable human settlement developments. However, environmental constraints such as dolomite has caused huge amounts of developable land loss as well as financial loss in the city. Consequently, the aim of this study is to assess the susceptibility of sinkhole prevalence in the city by comparing the Frequency Ratio and Analytical Hierarchy Process as a Multi Criteria Decision making method. 11 sinkhole factors were prepared including slope, elevation, soil type, rainfall, distance to rivers, water table, geology, land use, undermining, mining activity, degraded land, and vegetation. Susceptibility maps were then prepared using different methods. The receiver characteristic curve as well as the area under the curve (AUC) were developed for various susceptibility maps. The comparison of these two methods indicates that while the frequency method showed more accuracy in sinkhole occurrences the AHP is more commonly used by urban planners and can therefore be useful for risk disaster management in the City.
