Spatiotemporal Characteristics of Urban Land Expansion and Population Growth in Africa from 2001 to 2019: Evidence from Population Density Data

Africa has been undergoing a rapid urbanization process, which is critical to the achievement of the 11th Sustainable Development Goal (SDG11). Using population density data from LandScan, we proposed a population density-based thresholding method to generate urban land and urban population data in Africa from 2001 to 2019, which were further applied to detect the spatiotemporal characteristics of Africa’s urbanization. The results showed that urban land and urban population have both grown rapidly in Africa, which increased by about 5.92% and 4.91%, respectively. The top three countries with the most intense urbanization process in Africa are Nigeria, the Democratic Republic of the Congo, and Ethiopia. The coupling relationship index of urban land expansion and population growth was 0.76 in Africa during 2001–2019. Meanwhile, the total proportion of uncoordinated development types at the provincial level was getting higher, which indicated an uncoordinated relationship between urban land expansion and population growth in Africa. Cropland, grassland, rural land, and forests were the most land-use types occupied by urban expansion. The proportion of cropland, grassland, and forests occupied was getting higher and higher from 2001 to 2019. The extensive urban land use may have an impact on the environmental and economic benefits brought by urbanization, which needs further research.

[1]  B. Cohen.  Urbanization in developing countries: Current trends, future projections, and key challenges for sustainability , 2006 .

[2]  Alexandre Domingues,et al.  What Is Urban after All? A Critical Review of Measuring and Mapping Urban Typologies in Portugal , 2020, ISPRS Int. J. Geo Inf..

[3]  Hannes Taubenböck,et al.  The Physical Density of the City - Deconstruction of the Delusive Density Measure with Evidence from Two European Megacities , 2016, ISPRS Int. J. Geo Inf..

[4]  Longwu Liang,et al.  The effect of urbanization on environmental pollution in rapidly developing urban agglomerations , 2019, Journal of Cleaner Production.

[5]  Zhou Yi-xing.  Urban and Rural Area Division: Taking Shanghai as an Example , 2006 .

[6]  Weiqi Zhou,et al.  Dasymetric mapping of urban population in China based on radiance corrected DMSP-OLS nighttime light and land cover data. , 2018, The Science of the total environment.

[7]  Y. Liu,et al.  Evolution of Urban Spatial Clusters in China: A Graph-Based Method Using Nighttime Light Data , 2021, Annals of the American Association of Geographers.

[8]  Patrick Brandful Cobbinah,et al.  A Ghanaian twist to urban sprawl , 2017 .

[9]  D. Civco,et al.  THE DIMENSIONS OF GLOBAL URBAN EXPANSION: ESTIMATES AND PROJECTIONS FOR ALL COUNTRIES, 2000–2050 , 2011 .

[10]  Le Yu,et al.  Mapping global urban boundaries from the global artificial impervious area (GAIA) data , 2020, Environmental Research Letters.

[11]  K. Capps,et al.  Poverty, urbanization, and environmental degradation: urban streams in the developing world , 2016, Freshwater Science.

[12]  Sérgio Freire,et al.  Applying the Degree of Urbanisation to the globe: A new harmonised definition reveals a different picture of global urbanisation , 2020 .

[13]  J. E. Dobson,et al.  LandScan: Locating People is What Matters , 2002 .

[14]  K. Chan,et al.  Urbanization in China in the 1990s: New Definition, Different Series, and Revised Trends * , 2003 .

[15]  Katherine Anderson,et al.  Earth observation in service of the 2030 Agenda for Sustainable Development , 2017, Geo spatial Inf. Sci..

[16]  Mingguo Ma,et al.  Identification of Polycentric Cities in China Based on NPP-VIIRS Nighttime Light Data , 2020, Remote. Sens..

[17]  P. Cobbinah,et al.  Urban Sprawl and the Loss of Peri-Urban Land in Kumasi, Ghana , 2014 .

[18]  Xin Huang,et al.  An updated MODIS global urban extent product (MGUP) from 2001 to 2018 based on an automated mapping approach , 2021, Int. J. Appl. Earth Obs. Geoinformation.

[19]  I. Turok,et al.  Getting urban density to work in informal settlements in Africa , 2020 .

[20]  Yuyu Zhou,et al.  A harmonized global nighttime light dataset 1992–2018 , 2020, Scientific Data.

[21]  Noam Levin,et al.  A global analysis of factors controlling VIIRS nighttime light levels from densely populated areas , 2017 .

[22]  Michael O. Erdiaw-Kwasie,et al.  Africa's urbanisation: Implications for sustainable development , 2015 .

[23]  Zhe Zhu,et al.  Understanding an urbanizing planet: Strategic directions for remote sensing , 2019, Remote Sensing of Environment.

[24]  Fang Chuangli.  A review of Chinese urban development policy, emerging patterns and future adjustments , 2014 .

[25]  Jingzhu Zhao,et al.  Sustainable urban development: Policy framework for sustainable consumption and production , 2008 .

[26]  Zhenke Zhang,et al.  Detecting the Dynamics of Urban Growth in Africa Using DMSP/OLS Nighttime Light Data , 2020, Land.

[27]  Neema S. Sumari,et al.  Urban expansion and form changes across African cities with a global outlook: Spatiotemporal analysis of urban land densities , 2019, Journal of Cleaner Production.

[28]  Weiqi Zhou,et al.  A novel approach for quantifying high-frequency urban land cover changes at the block level with scarce clear-sky Landsat observations , 2021 .

[29]  Population Density and Spatial Patterns of Informal Settlements in Nairobi, Kenya , 2020 .

[30]  K. Seto,et al.  Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools , 2012, Proceedings of the National Academy of Sciences.

[31]  P. Cobbinah,et al.  Stewardship of Urban Greenery in an Era of Global Urbanisation , 2014 .

[32]  F. Creutzig,et al.  Future urban land expansion and implications for global croplands , 2016, Proceedings of the National Academy of Sciences.

[33]  P. Cobbinah,et al.  MANAGING PHYSICAL DEVELOPMENT IN PERI-URBAN AREAS OF KUMASI, GHANA: A CASE OF ABUAKWA , 2013, Journal of Urban and Environmental Engineering.

[34]  Tim Dyson,et al.  The role of the demographic transition in the process of urbanization. , 2011, Population and development review.