Population grids
Gridded population: GHSL, WorldPop and census grids, totals per area, density per square kilometre, change since 1975, degree of urbanisation, and the cell-area, resampling and suppression traps that change the count.
Population grids estimate how many people live in each cell of a regular grid: modelled global products such as the GHSL’s GHS-POP and WorldPop, and census grids such as Statistics Netherlands’ 100 m squares, which count registered residents at their addresses. The guides here download and clip them, sum them by area without gaining or losing people at the edges, compare them, map change since 1975, and convert them to density per square kilometre.
The examples use the Netherlands, where a census grid and official counts exist to check the models against. GHS-POP 2020 comes within 0.11% of the 17,407,585 residents registered on 1 January 2020, its 2025 projection is 2.0% short of the count that followed, and the census grid itself adds up to 666,800 fewer people than the official total, because of how it is published.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Download and Clip the GHSL Population Grid in Python
- How to Download and Use a WorldPop Population Raster in Python
- How to Use a Census Population Grid in Python
- How to Map Population Change Since 1975 with GHSL in Python
- How to Classify Degree of Urbanisation with GHSL in Python
- How to Sum a Population Grid by Municipality in Python
Show every how-to guide in this topic
- How to Map Population Density per km² from a Population Grid in Python
- How to Compute Population-Weighted Density in Python
- How to Resample a Population Grid to Another Resolution in Python
- How to Compare Population Grids Cell by Cell in Python
- How to Map Age Groups from a Census Population Grid in Python
- How to Measure Built-Up Area per Person with GHSL in Python
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
- Fixing a Census Grid Total That Comes Out Below the Official Population
- Fixing Population Totals That Add Up to More Than the Whole
- Fixing Population Densities That Are Wrong on Latitude-Longitude Grids
- Fixing a Population Total That Changes After Reprojecting the Grid
- Fixing Negative Populations and Values in Census Grid Data
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Subjects that keep coming up alongside this one, most overlap first.