The Sahel and West Africa Club (SWAC) is an independent, international platform. Its Secretariat is hosted at the Organisation for Economic Co-operation and Development (OECD). Its mission is to promote regional policies that will improve the economic and social wellbeing of people in the Sahel and West Africa.

Africa has the fastest urban growth in the world. The continent’s population is projected to double between now and 2050. Two-thirds of this growth will be absorbed by urban areas and, in the next 30 years, cities will be home to an additional 950 million people. This offers great opportunities, but also challenges for African citizens, businesses, governments and their partners. The political development agenda needs to be revamped as policy decisions taken today will have lasting consequences for generations.

The pace of urbanisation in Africa over the last 60 years is without precedent. In 2015, Kenya had more urban dwellers than the entire continent combined in 1950. Africa’s urban population in 2015 was 567 million people, compared to 27 million in 1950. Africa will continue to have the fastest urban growth in the world. The continent’s population is projected to double between now and 2050 and two-thirds of this growth will be absorbed by urban areas. This means that in the next 30 years Africa’s cities will be home to an additional 950 million people.

The definition of what constitutes a city or urban area differs between countries or institutions according to the criteria used, including political-administrative, morphological or functional. The chosen definition will influence urban statistics including on the number of cities, urban population or population density. The variety of existing definitions strongly limits the comparability of urban statistics across countries. Africapolis defines and applies one homogeneous spatial definition to provide a comparable measure of urban phenomena across countries and time. Its spatial approach makes it possible to describe key features of African urbanisation dynamics, such as urban sprawl, in situ urbanisation of rural areas and the emergence of metropolitan regions. In addition to promoting a harmonised use of definitions, Africapolis re-evaluates certain “myths” regarding African urbanisation — such as rural exodus — allowing for the design of policies that reflect current urban realities.

With 7 617 urban agglomerations of more than 10 000 inhabitants identified by Africapolis in 2015, Africa is urbanising at an astounding pace. Africa’s urban transition is more diverse and multifaceted than commonly conceptualised. Its drivers, patterns and outcomes are not following uniform and past processes. The absence of more comprehensive data has clearly contributed to current misconceptions about urbanisation in Africa. Yet, the design of appropriate policy interventions depends on better understanding the realities and contextual differences of African urbanisation dynamics.

The first part of Chapter 3 analyses the demographic, political and environmental factors that influence urban growth in Africa. Africa has transitioned from a period of demographic stagnation dating to the pre-colonial era to a period of positive growth in the colonial era, followed by exponential growth after independence. Since the beginning of the 2000s, globalisation has left its mark on settlement patterns. Political conditions have shaped urban phenomena — the impact of urban planning (or its absence) is visible in satellite imagery, and administrative boundaries often do not match those of existing agglomerations. Finally, environmental constraints like the availability of water or land have major influences on urban growth, as demonstrated by the agglomerations of the Nile River valley or in Rwanda. In the second part, this chapter highlights different “spatial attractors” (points, lines and surfaces) used to model urban dynamics. The analysis of growth factors and modelling reveals new aspects of urban growth in Africa: the increasingly blurred distinction between urban and rural, dispersed urbanisation and chaotic forms of agglomeration.

This chapter explores the characteristics of large agglomerations and the variety of recent forms of urbanisation on the African continent. The hierarchy of national urban systems are characterised by the large size of metropoles relative to intermediary cities, and high primacy indices relative to the rest of the world. New forms of urbanisation are appearing: the development of small and medium agglomerations forming large metropolitan regions, conurbations and megaagglomerations. These agglomerations spread spontaneously in areas that are officially considered rural, though already densely populated, and notably in the interior of the continent.