Sources
Every map on this site is built from open data. These are the datasets, what each one contributes, and the licence it comes under.
- Natural Earth
Country and region boundaries, lakes, river courses
Public domain
- Copernicus DEM (GLO-30 / GLO-90)
Elevation data for Iceland, the Netherlands, Scandinavia and Canada
© DLR e.V. 2010–2014 and © Airbus Defence and Space GmbH 2014–2018, provided under COPERNICUS by the European Union and ESA
- NASA SRTM
Elevation data for most of the world between 60° N and 56° S
Public domain (NASA / USGS)
- ETOPO 2022
Elevation and bathymetry where SRTM does not reach — the Arctic, Antarctica, the ocean floor
Public domain (NOAA National Centers for Environmental Information)
- HydroSHEDS / HydroRIVERS
The river network drawn on each map
Free to use with attribution (WWF)
- GeoNames
City names, populations and marker positions
CC BY 4.0
- geoBoundaries
Administrative boundaries below national level
CC BY 4.0
- OpenStreetMap (via Nominatim)
Selected city outlines for Munich, Berlin and Hamburg
© OpenStreetMap contributors, Open Database License (ODbL)
- GHS Urban Centre Database (R2024A V1.2)
Urban area outlines worldwide, selected from centres with at least one million inhabitants in 2025 and generalised for display. Selected outlines use OpenStreetMap or US Census boundaries. In Bihar and Kerala, diffuse population clusters are omitted or restricted to compact built-up cores.
© European Union, European Commission, Joint Research Centre (JRC). Reuse authorised with acknowledgment of the source.
- US Census Bureau — corrected 2020 Census Urban Areas
Dallas–Fort Worth and Houston urban outlines, generalised from the 1:500,000 cartographic boundaries
Public domain (US Census Bureau)
- GHSL — Global Human Settlement Layer
Population grid behind the “people affected” figure; GHS-BUILT-S R2023A building surface for refining selected Indian city outlines (2020, 100 m)
CC BY 4.0, European Commission, Joint Research Centre
The maps themselves are computed from these datasets in house. How the result is meant to be read, and what it deliberately leaves out, is described under Method.