The development and use of a land–use suitability model in spatial planning in South Africa

Abstract

The United Nations (UN, 2006) predicts that 61 % of the world population (approximately 4.9 billion people) will be living in urban settlements by the year 2030. It is further anticipated that most of this urbanization will take place in developing countries, and more specifically in Africa. This is most likely due to the fact that most African countries are currently in an urban transition phase, as they are systematically changing from predominantly rural societies to predominantly urban societies. Urban growth is a definite reality and poses a threat to the natural environment around urban areas, and in effect also to urban sustainability. To assist planners and governments in effectively planning for urban growth and to ensure sustainable development, they need optimal decision support systems to aid them in the development of land-use management policies and spatial development plans. It is crucial that these support systems be comprehensive, to encourage sustainable development in a proactive manner. One way to assist planners and governments in this crucial task, is by providing them with land-use suitability and urban growth scenarios, which may assist them in the development of spatial development frameworks (SDF) and policies. Although a great deal of research has been done internationally on urban growth modelling, it is poorly researched in South Africa. This study employs a multiple-criteria approach to analyse land-use conflicts as well as land-use suitability via a Geographical Information System-based weighted overlay procedure. The analysis takes three competing land-uses (urban, agriculture and conservation) into consideration, in an attempt to identify the most suitable land available for each land-use. The results are ultimately used as inputs for urban growth modelling. A successful urban growth scenario was achieved for the city of Potchefstroom, North West, South Africa for the year 2030. The study showed that a fairly uncomplicated approach to urban growth modelling is possible with readily available data in South Africa and that such an approach has value for spatial planning purposes.