EXECUTIVE SUMMARY
Geospatial population data products — fine-resolution gridded estimates of where people live — have become essential tools for UNFPA's census support, health planning, and humanitarian response work. This document provides a focused analysis of the major geospatial population data initiatives that UNFPA partners with, their methodologies, strengths, limitations, and applications to SRHR planning. It complements the broader technology overview in UNFPA-T-03 with deeper detail on specific data products and their use cases.
The three most significant geospatial population data products for UNFPA's work are: WorldPop (University of Southampton), which produces open-access gridded population datasets at approximately 100m resolution using satellite imagery and statistical modelling; GRID3 (Geo-Referenced Infrastructure and Demographic Data for Development), a multi-partner initiative supporting government production and use of geospatial data in approximately 10 countries; and Meta's High Resolution Settlement Layer, which uses AI to detect building footprints from satellite imagery and estimate population density.
UNFPA uses these products for: delineating census enumeration areas, estimating populations in areas without recent census data, mapping health facility coverage gaps, targeting SRHR commodity distribution, and estimating affected populations in humanitarian crises. The integration of geospatial data into UNFPA's routine programming is advancing but remains uneven across country offices.
KEY FACTS
- WorldPop: Covers virtually all countries; approximately 100m resolution; open-access; uses random forest models combining census data with satellite-derived covariates
- GRID3: Active in approximately 10 countries (Nigeria, DRC, Zambia, Sierra Leone, and others); focuses on government capacity building
- Meta HRSL: Uses AI to detect individual buildings from satellite imagery; identifies settled vs unsettled areas at very high resolution
- LandScan: Oak Ridge National Laboratory product; approximately 1km resolution; widely used by humanitarian community
- Census integration: UNFPA supports countries in using geospatial tools for enumeration area delineation, sampling frame development, and fieldwork planning
- Accuracy: Validation studies show gridded population estimates within 10–20% of census counts at sub-national levels in well-modelled countries; accuracy decreases in data-scarce environments
- Open access: WorldPop and Meta datasets are freely available; promotes use by governments, researchers, and NGOs
DETAIL
Applications for SRHR Planning
Health facility accessibility: Combining geospatial population data with health facility locations enables calculation of travel time to nearest SRHR facility. This reveals "SRHR deserts" — populated areas beyond 2-hour travel time to EmONC. Such analyses have informed health facility investment decisions in Nigeria, Mozambique, and DRC.
Contraceptive distribution targeting: Overlaying population density with modern CPR estimates (from surveys) and supply chain data enables UNFPA to target commodity distribution to highest-need areas.
Census support: Satellite imagery enables updating of enumeration area boundaries to account for urbanisation, new settlements, and displacement — improving census accuracy.
Humanitarian response: During rapid-onset emergencies, geospatial population estimates provide immediate affected-population numbers before ground assessments are possible.
SOURCES
- WorldPop (worldpop.org): Methodology and datasets
- GRID3 (grid3.org): Country programme documentation
- Meta Data for Good: High Resolution Settlement Layer
- Tatem, A.J.: "WorldPop, open data for spatial demography" (Scientific Data, 2017)
RELATED DOCUMENTS
- UNFPA-T-03 (Geospatial Data — broader overview)
- UNFPA-D-02 (Census and CRVS)
- UNFPA-T-05 (AI in Population Health)
- UNFPA-T-04 (Supply Chain Innovation)