Climate

African cities are important places to focus climate action. They are considered “extremely at risk” by the Climate Change Vulnerability Index and therefore need data and decision-making tools. In the context of rapid urbanization, better planning toward a more sustainable, compact urban form is critical.

A more compact city means better access to services, less travel, less energy consumption by vehicles, and therefore less emissions and pollution. To measure compactness, SWAC developed two indicators for 5,625 African urban agglomerations.

Firstly, sprawl measures the amount of space between buildings. A value of 1 means that the agglomeration is compact, > 1 indicates increasing sprawl. Secondly, elongation measures the tendency of the buildings to form a circle, which is the most compact urban form. A value of 1 means that the agglomeration is a circle. Higher values indicate that the shape becomes more elliptical.

MEASURING URBAN COMPACTNESS

Data sources

Two data sources are combined. SWAC/Africapolis defines urban agglomerations using two criteria: i) an area with  10,000 or more inhabitants and ii) a continuously built-up area with less than 200 meters between buildings. Open Buildings provides the location and size of the footprint of the buildings. Other indicators displayed in the map pop-up combine Africapolis with OpenStreetMap and building height data from the German Aerospace Center (DLR). For a detailed description of the calculation of these indicators, please consult this document.

Citation:

OECD/SWAC (2023), “Green Spaces and Urban Form Dataset”, Mapping Territorial Transformations in Africa (MAPTA), https://mapping-africa-transformations.org/climate (accessed on DD-MM-YYYY).