International Journal of Geo-Information Article Spatiotemporal Characteristics of Urban Land Expansion and Population Growth in Africa from 2001 to 2019: Evidence from Population Density Data Shengnan Jiang 1,2 , Zhenke Zhang 1,2,3,*, Hang Ren 4 , Guoen Wei 1,2 , Minghui Xu 1,2 and Binglin Liu 1,2,3 1 School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China;
[email protected] (S.J.);
[email protected] (G.W.);
[email protected] (M.X.);
[email protected] (B.L.) 2 Institute of African Studies, Nanjing University, Nanjing 210023, China 3 Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210093, China 4 Institute of Population Studies, Nanjing University of Posts and Telecommunications, Nanjing 210042, China;
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[email protected]; Tel.: +86-25-8968-6694 Abstract: Africa has been undergoing a rapid urbanization process, which is critical to the achieve- ment 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%, Citation: Jiang, S.; Zhang, Z.; Ren, respectively. The top three countries with the most intense urbanization process in Africa are Nigeria, H.; Wei, G.; Xu, M.; Liu, B.