High-Resolution Population Mapping and the Example of South Sudan

The U.S. Census Bureau develops and provides geo-enabled population data sets, based on census and survey data, administrative geography, and satellite imagery. The Demobase gridded mapping program aims to create high-resolution national population map layers, using imagery and census and survey data. Data sets for Haiti, Pakistan, and Rwanda have been available for several years. Mapping of the latest and most challenging country, South Sudan, was recently completed. South Sudan is unusually difficult for gridded mapping because of its lack of current census data, largely rural population, and extensive recent changes in population distribution. South Sudan is an advance on previous Demobase efforts in several ways, including incorporation of data from Protection of Civilian (refugee) sites, creation of a current-date population layer along with one for the census year, use of Sentinel-2 imagery, a focus on land affected by human activity rather than just built-up area, and more extensive use of ancillary data sets such as water facilities. The resulting layers show population distribution in great detail and provide insights into how population clusters near landscape features such as rivers. Census Bureau international data products are used by government, charitable, educational, and research organizations. Our primary goal is to provide the maps and population data required for humanitarian assistance and disaster relief efforts globally. The demand for these data for crisis response has been demonstrated, most notably by users of our Haiti products after the 2010 earthquake.