Docs
How to find a dataset, get the files for your region and cite them.
Finding data
Pick a category on the left of the home page, or search from the box at the top of any page (press /). Search matches dataset names, variables and providers, and also places: river basins, rivers, lakes, reservoirs, gauge stations, towns and coordinates such as -3.1, -60.2.
The dataset list filters by category, access type, global or regional coverage and provider.
Regions
Draw a box on the map with the region button, or hold Shift and drag. Clicking a basin, gauge or reservoir offers Use as region, and choosing a basin or lake in the search box selects it. With a region set, the list below the map shows only datasets that cover it, and the links, manifest and code examples in the side panel follow it.
The region is part of the page address, so a link to the page keeps it.
Getting links
Get links lists what the provider offers for the region:
| Method | What you get |
|---|---|
| Tiles | The tile files that intersect the region, for datasets published as fixed grids (Copernicus DEM, ESA WorldCover, Global Forest Change, Global Surface Water, FABDEM). Tile lists are checked against the provider's own index where one exists. |
| NASA Earthdata | Granules found live through NASA's Common Metadata Repository (SRTM, ASTER GDEM, NASADEM, MODIS, SMAP, IMERG, GRACE). Downloads need a free Earthdata login. |
| STAC | A search against the provider's STAC API (Sentinel-2, Landsat, Copernicus DEM). |
| API | A ready-made request to the provider's own service for the region, such as a clipped GeoTIFF or a station list. |
| Provider page | For data that needs a registration or a request, the page where that happens. |
Code examples
The cURL, Python and JavaScript tabs are ready to run for the current region. They use the provider's usual client where there is one (earthaccess for NASA, cdsapi for Copernicus, pystac-client for STAC, the Earth Engine API) and this site's links API otherwise.
Manifests
A manifest is a small JSON file with the dataset record, its licence and citation, the region, the time it was made and every link. Keep it next to the downloaded data so the provenance travels with it.
Access types
| Label | Meaning |
|---|---|
| Direct download | Files download without an account. |
| Download with free login | Files need a free account with the provider, usually NASA Earthdata. |
| API | Data comes from a web service; some need a free key. |
| Cloud platform | Data is used inside a platform such as Google Earth Engine. |
| Registration with provider | The provider sends access after a registration form. |
| Request from provider | Data is ordered through the provider's portal under its data policy. |
Map layers
The map layers help with finding and framing a region. They are generalised for display; use the datasets themselves for analysis.
| Layer | Source |
|---|---|
| Basins | HydroBASINS level 4 merged to whole river basins, the 300 largest (over 100,000 km²). Names come from the Natural Earth river that reaches each basin's outlet. |
| Rivers, lakes | Natural Earth river centrelines (1:10m) and lakes (1:50m). |
| Reservoirs | Natural Earth lakes classed as reservoirs, with dam names where recorded. |
| Gauge stations | 30,935 stations from the GSIM catalogue, excluding those flagged for suspect coordinates. Stations with catchments of 5,000 km² and more show first; the rest load when you zoom in. |
Map data credits
- Base map: OpenFreeMap, © OpenStreetMap contributors, OpenMapTiles.
- Blue Marble shaded relief and the dataset previews marked NASA GIBS: NASA Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System.
- Natural relief, rivers, lakes, reservoirs and ocean names: Natural Earth (public domain).
- Basins: HydroBASINS, Lehner, B., Grill, G. (2013), Hydrological Processes, 27(15), 2171–2186. Data available at www.hydrosheds.org.
- Gauge stations: GSIM, Do, H. X., Gudmundsson, L., Leonard, M., Westra, S. (2018), doi:10.1594/PANGAEA.887477, CC BY 4.0.
- Relief previews: Terrain Tiles on AWS (Mapzen), built from SRTM, GMTED2010, ETOPO1 and national elevation data.
- Place search: Photon by komoot, on OpenStreetMap data.
Adding a dataset
Signed-in users can suggest a dataset. A dataset belongs here if it is useful for hydrology, is published by an identifiable provider with stated terms, and can be reached by anyone, even if a free registration is needed.