Slum and urban deprivation in compacted and peri-urban neighborhoods in sub-Saharan Africa

UN-Habitat estimates that 51.3% of the urban population in sub-Saharan Africa (SSA) resided in slums in 2020, and future projections indicate continued growth. However, limited information on the spatial distribution and evolution of slums in the region underestimates the challenges they present. This study investigates the use of urban morphology to map slums in 95 cities across Nigeria, Kenya, Ghana, and Malawi. The approach employed an unsupervised classification and a tree-based clustering framework, integrating morphological and socio-economic indicators, as well as comprehensive sampling points for slums. Our findings indicate that morphological clusters with compact, small buildings are indicative of a high prevalence of slums, with an accuracy rate of 83.6%. Moreover, these morphological slum clusters exhibit significant correlations with socio-economic indicators, exhibiting lower GDP and wealth index compared to neighbouring clusters. Notably, larger and older cities with morphological slum clusters demonstrate improved economic well-being and enhanced access to infrastructure. Our findings underscore the potential of utilizing urban morphology to comprehend the diversity and dynamics of urban slums and socioeconomic development. These results provide a foundation for large-scale identification of slums and urban deprivation, offering support for targeted solutions to address the challenges associated with slums in developing countries.