Variability in urban population distributions across Africa

Abstract

Africa is projected to add one billion urban residents by 2050. Yet developing sustainable solutions to tackle the host of challenges posed by rapid urban population growth is stymied by a lack municipality-level population data across the continent. To fill this gap, we intersect volunteered urban settlement data from OpenStreetMap with five synthetic gridded population datasets to estimate the how Africa's urban population is distributed among over 4750 individual urban settlements across Africa. We assess how urban settlement distributions changed from 2000 to 2015 within and between countries and across moisture zones. To this end, we construct urban settlement Lorenz curves to calculate change in Gini coefficients and test the degree to which Africa's urban settlements distributions fit power law distributions exhibited by Zipf's law. Our results reveal that 77%-85% of urban settlements in Africa have fewer than 100 000 people and that at least 50% of Africa's urban population live in urban settlements with fewer than 1 million residents. Across almost all African countries, the distribution of urban population shifted towards larger cities between 2000 and 2015. However, in arid regions, our results indicate that small-and medium-sized urban settlements are absorbing a greater share of urban population growth compared to large urban settlements. While our urban population estimates vary across gridded population datasets and differ from United Nations estimates, this is the first paper to measure urban population across Africa using a consistent methodology to identify urban settlement populations. Unlike UN urban population data for Africa, our results can readily be incorporated with geolocated environmental, public health, and economic data to support efforts to monitor United Nations Sustainable Development Goals related to urban sustainability, poverty reduction, and food security across Africa's ever-growing urban settlements.

Urban malaria in sub-Saharan Africa: dynamic of the vectorial system and the entomological inoculation rate

“…The urban population which was estimated at 491 million in 2015 is projected to grow to nearly 1.5 billion by 2050 [10]. However the rapid unplanned urbanization observed in many sub-Saharan Africa cities characterized by the colonization of lowland areas for house construction, the absence of drainage system for water, the presence of standing water collection everywhere due to the bad state of roads and poor housing are all considered to affect the distribution of vector population and malaria transmission pattern [11].…”

High-Resolution Gridded Population Datasets: Exploring the Capabilities of the World Settlement Footprint 2019 Imperviousness Layer for the African Continent

“…Countries such as Burkina Faso, Kenya, Madagascar and Malawi, for example, carried out their last population census between 2018 and 2019, while approximately 80% of the African countries conducted their last census between 2005 and 2015. However, limited financing and poor budgeting strategies for data collection are concurrent issues in many African countries, which result in incomplete or outdated demographic statistics [19]. Under any context, from policy making to scientific research, acquiring up-to-date population data at the highest available resolution should remain the main priority [27].…”

“…This was highlighted in the reviews presented by Kavvada et al [4], Kuffer et al [7], and Qui et al [10], where the authors argue that geospatial data related to human population distributions could potentially be used to directly or indirectly support, implement and monitor more than half of the SDGs (~11 out of 17 SDGs) and a large proportion of their related indicators (~98 of the 231 Indicators). Research in the fields of public security [11], health policy [12][13][14], network and transportation [15], vulnerability and risk assessment [16][17][18], urban growth [19] and mitigation [20] among others, are examples of the many areas where these datasets are needed as inputs to produce reliable information.…”

Study on the Coupling Coordination of Urban Infrastructure and Population in the Perspective of Urban Integration

“…From 1989 to 2007, the built-up area of Sana'a, the capital of Yemen, increased by 87%, but the population almost doubled every decade, and the urban infrastructure was under great pressure [39]. The number of urban residents in Africa is expected to soar from 491 million in 2015 to nearly 1.5 billion in 2050, which brought great pressure to cities [40]. Tabuchi (2014) insist that urban population growth and urban development must be coupled [41].…”

“…The above researches are mostly attributed to the single study of urban infrastructure construction issues and urban population problem [39]- [40][41], which only focus on the relationship between transportation infrastructure, energy infrastructure and urban population in a single range [55]- [56], analyzing the relationship between urban population and infrastructure in a qualitative way [53][54] [57[][60], There is a lack of quantitative evaluation research on the supply level of urban infrastructure and the development level of urban population, and the research on the coupling relationship between urban infrastructure and urban population is almost blank. Based on the above analysis, we establish the coupling coordination model of urban infrastructure and urban population, analyze the coordination and then conduct the case study to explore the relationship between infrastructure and population in the integration process of Qingdao, Yantai and Weihai, China, verify the applicability of the coupling coordination model of urban infrastructure and urban population.…”