Supporting countries with population mapping and estimations is a key part of our work. Our peer-reviewed estimation methods have led to, for instance, five million more children in Afghanistan receiving vaccines against diseases such as polio, measles, mumps and rubella1. In northern Nigeria, our data estimates were used in the successful elimination of polio2.
As governments work to improve health and education through sustainable development detailed population data is in greater demand. However, some countries have not conducted a census for more than 20 years, and there are many countries that were supposed to do a census in 2020 or 2021 but were unable to because COVID-19 led to their budget being removed or prevented them from carrying out in-person door-to-door surveys. Even in places where high quality censuses are conducted every ten years, population numbers and distributions can change rapidly in small areas and be hard to predict through traditional projection methods.
A lot of our work is with UN agencies3 and national governments on developing ways to produce population estimates using geospatial methods and data. This involves working with many datasets that have been built from, for example, local surveys and satellite imagery4.
In a few countries, estimates from WorldPop have been used to fill gaps where a census has been conducted, but certain areas could not be included because they were inaccessible due to insecurity5,6. We have been able to provide them with a way to fill those data gaps, and this information is used as official statistics to allocate aid, resources, and representation in parliament.
How accurate are population estimates?
Population estimation methodologies use a range of data-driven techniques and are vital in supporting decision making in the absence of a properly conducted census. However, there are always limitations, for example WorldPop researchers have highlighted that without sufficient training data, population estimation methods may systematically under-represent numbers of people living in slums7,8.
Video: What are gridded population estimates?
Produced by our partners at GRID3, the video below provides a useful overview of how our high-resolution gridded population estimates are enabling decision making in support of sustainable development goals.
- Mapping Afganistan’s population
- Outside the box: how Nigeria won the fight against polio
- UNFPA: The Value of Modelled Population Estimates for Census Planning and Preparation
- Spatially disaggregated population estimates in the absence of national population and housing census data
- High-resolution population estimation using household survey data and building footprints
- The Population Seen from Space: When Satellite Images Come to the Rescue of the Census
- How accurate are WorldPop-Global-Unconstrained gridded population data at the cell-level?
- Improving the accuracy of gridded population estimates in cities and slums to monitor SDG 11
Image: Unequal Scenes – Durban, South Africa by Global Landscapes Forum, 2016 (cc by-nd-nc 2.0)