Transparency

Data sources

Every figure on this site comes from a public dataset with a licence that allows this use. Here is each one, what we take from it, and how.

Source	What we use	Period	Licence	Attribution
Copernicus DEM GLO-30	Copernicus DEM GLO-30 (Cloud Optimized GeoTIFF, AWS Open Data)	2011-2015 (TanDEM-X)	Copernicus WorldDEM-30 licence (free, worldwide, incl. commercial use)	Relief, cuts and 3D models produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved. The organisations in charge of the Copernicus programme by law or by delegation do not incur any liability for any use of the Copernicus WorldDEM-30
EOX Sentinel-2 cloudless 2016	s2cloudless 2016 (layer s2cloudless_3857)	2016	CC BY 4.0	Satellite images: Sentinel-2 cloudless 2016 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0
GeoNames	cities1000 (towns with 1,000+ people, with elevation) and countryInfo		Creative Commons Attribution 4.0	Towns from GeoNames (CC BY 4.0)
HydroATLAS (RiverATLAS)	RiverATLAS v1.0: the river in the canyon: long-term average discharge and the lowest and highest month (WaterGAP 1971-2000), upstream area, river order	1971-2000 (discharge model)	CC BY 4.0	River flow and catchment area: HydroATLAS / RiverATLAS v1.0, Linke et al. 2019, Scientific Data 6: 283 (CC BY 4.0); discharge from WaterGAP v2.2
NASA POWER	Climatology, monthly and daily point data (MERRA-2 / CERES SYN1deg)	1991-2020 averages; 2020-2025 month by month; daily rain 1991-2025	CC BY 4.0 (NASA open data)	Climate: the data was obtained from the NASA Langley Research Center POWER Project funded through the NASA Earth Science Division
OpenFreeMap	Vector base map (OpenStreetMap data)		ODbL 1.0 (OSM data)	Base map © OpenStreetMap contributors, OpenFreeMap
OpenStreetMap	Viewpoints, trails, via ferrata, climbing, footbridges, rafting spots, caves, parking, campsites and the river line around each canyon (Overpass API)		Open Database License (ODbL) 1.0	Viewpoints, trails, bridges and rivers around each canyon © OpenStreetMap contributors (ODbL)
OurAirports	airports.csv		Public domain	Airports from OurAirports (public domain)
Wikidata	Canyons and gorges: names in 7 languages, published depth, length and width, elevation, river, protected area, World Heritage, images		CC0 1.0 (public domain)	Canyon names, published depths, lengths and rivers from Wikidata (CC0)
Wikimedia Commons	Photographs of each canyon (Wikidata P18, Commons category, English Wikipedia article, geosearch)		Per file: public domain, CC0, CC BY or CC BY-SA only	Photos from Wikimedia Commons; author and licence under each photo
flag-icons	Country flags in SVG (4:3)		MIT	Country flags from flag-icons (MIT licence)

The canyons

Each canyon is an item in Wikidata (CC0): canyons, gorges, ravines, slot canyons, water gaps and coastal gorges with coordinates. From it come the names in seven languages, the published depth, length and width, the river, the protected area, World Heritage status and the main photograph. A canyon gets a page when enough Wikipedias write about it.

The cut

Depth, width, the wall and the 3D model are measured on the Copernicus DEM GLO-30, the European relief model at 30 m. We find the lowest point near the published coordinate, cut 18 lines through it and keep the deepest and narrowest. Depth is to the lower rim. A 30 m model smooths the narrowest slots, so we always show the published depth too where there is one.

Climate

Temperature, rain, rainy days, sun and snow come from NASA POWER (1991–2020 averages, and each month since 2020) for a cell about 55 km wide, at the average altitude of that cell. We bring the temperature to the rim and to the floor with the standard lapse rate, 6.5 °C per 1 000 m: that is why the floor is warmer. The best months to hike are an estimate from these averages.

The river

The flow of the river in the canyon comes from HydroATLAS (RiverATLAS, CC BY 4.0): the long-term average and the lowest and highest month of the WaterGAP model (1971–2000), for the river reach that runs through the floor. The shape of the year comes from the rain, snow and temperature of the area. It is an estimate, and dams change it.

Around the canyon

Viewpoints, trails, via ferrata, climbing crags, bridges, rafting spots, caves, car parks, campsites and the line of the river come from OpenStreetMap (ODbL), the map anyone can edit. We count what is there within a few kilometres of the floor. A low number may just mean nobody has mapped it yet. Nothing from OpenStreetMap goes into the files the map and the search download: it stays inside the pages.

Images

The views from above are the Sentinel-2 cloudless 2016 mosaic by EOX (CC BY 4.0), shaded with the Copernicus relief. Photographs come from Wikimedia Commons, only under licences that allow commercial use, with the author and licence under each one.