Visualising urbanisation: How the Africapolis platform sheds new light on urban dynamics in Africa

By Lia Beyeler, Communications Officer and Nisha Schumann, Consultant, Sahel and West Africa Club Secretariat (SWAC/OECD)

Africa’s urban population is the fastest growing in the world. By 2050, Africa’s cities will be home to nearly one billion additional people. Yet, where and how Africa’s cities of the future emerge and evolve are insufficiently understood.

Traditionally, the focus has been put on larger cities as opposed to smaller urban agglomerations. Yet, smaller agglomerations with populations between 10,000 and 100,000 inhabitants represent one-third of Africa’s overall urban population, accounting for more than 180 million people in 2015. Their significance is highlighted by the fact that many of the continent’s future cities are emerging through the fusion of smaller cities or through population densification in rural areas – trends that are not captured in official statistics and government data, which tend to focus on cities as political units with defined boundaries.

The OECD Sahel and West Africa Club’s Africapolis platform, which launched during the 8th Africities Conference in Marrakesh, seeks to bridge the gap in data on African urbanisation dynamics. It provides a powerful tool for governments, policy makers, researchers and urban planners to better understand urbanisation’s drivers, dynamics and impacts. This understanding, in turn, will help design more relevant policies that address the growing challenges of urbanisation at the local, national and regional levels.

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Several key features of the Africapolis platform make it a particularly relevant tool for supporting policy makers in making Africa’s cities of the future more resilient, inclusive and sustainable.

First, the Africapolis database includes data on more than 7 500 urban agglomerations in 50 countries and a variety of data visualisation aids. By covering all agglomerations above 10,000 inhabitants, Africapolis provides a more complete set of data than any other existing database. The platform allows users to browse, download and reuse more than 200,000 data points, including data on population numbers, population densities, geo-location of urban agglomerations, built-up areas and average distances between urban agglomerations ranging back to 1950. In addition to the raw data, users can also use the embedded data visualisation tools, including maps and charts, to explore and compare urbanisation dynamics within and between countries.

Second, Africapolis takes a bottom-up approach to defining urban agglomerations, one that presents a more accurate reflection of the realities on the ground. It combines official census data, cartographic resources and satellite imagery to identify the extent of built-up areas and to provide population estimates based on the observed information on the ground. By using the same methodology across the 50 countries, Africapolis is the first database to provide a standardised and comparable measure of urbanisation.

This spatial or morphological approach can remedy some of the ambiguities that currently exist in official urban population estimates that are based on definitions of cities as administrative units, which vary from country to country and often fail to capture the reality of where people live. For example, Kinshasa’s official boundaries include several administrative units that consist mainly of sparsely inhabited forestland. By combining the reported population figures for Kinshasa with the officially defined boundaries of the city, some could infer that Kinshasa has one of the lowest population densities of any capital in the world. By contrast, the morphological approach, which clearly delineates the boundaries of the urban agglomeration according to the built environment, shows that Kinshasa is, in fact, one of the planet’s most densely populated cities.

Third, the Africapolis platform includes compelling narratives that de-bunk some of the common myths about urbanisation in Africa. For instance, Africapolis data reveal that urbanisation and the emergence of large agglomerations are not necessarily the result of a rural exodus but the contrary: the densification of rural areas and the merger of smaller settlements into larger ones. Consider, for example, the urban agglomeration of Onitsha in Nigeria. It officially has a population of 1.1 million inhabitants (World Urbanization Prospects, 2018), but in reality the urban agglomeration spreads over an area 80 times larger than the city itself with a population of 8.5 million according to Africapolis estimates. Similar examples abound in Africa and highlight the need for policy makers to better integrate the drivers and impacts of urbanisation dynamics.

As governments continue their efforts towards the vision laid out in the New Urban Agenda and to meet the targets of Sustainable Development Goal 11 to “make cities and human settlements more inclusive, safe, resilient and sustainable”, Africapolis could not be timelier. It is a crucial resource to guide governments, policy makers and urban planners in designing adequate, relevant and data-driven responses for a managed and sustainable urban transition. Africapolis, therefore, can play an important role in ensuring that future trends are anticipated and acted upon with the most reliable data at hand.