dataset · Global
MERIT Hydro: Global Hydrography Datasets
MERIT Hydro is a new global flow direction map at 3 arc-second resolution (~90 m at the equator) derived from the version 1.0.3 of the MERIT DEM elevation data and water body datasets (G1WBM, GSWO and OpenStreetMap). MERIT Hydro contains the output of a new algorithm that extracts river networks near-automatically by separating actual inland basins from noise caused by the errors in input elevation data. After a minimum amount of hand-editing, the constructed hydrography map shows good agreement
Visit source ↗Source details
Licence: ODbL-1.0
Evidence quality: 37.7
Listed in gee public catalogue API on 2026-10-16; relevance/value screened (haiku).
Metadata checked: 2026-10-14T13:20:00.000Z
What's in it
- Data offered docs-verified
- elevation (elv) · flow direction (dir) · river channel width (wth) · permanent water (wat) · upstream drainage area (upa) · upstream drainage pixel count (upg) · hydrologically adjusted elevation / HAND (hnd) · river width visualisation (viswth)
- Coverage docs-verified
- Global, between 90N and 60S · 1987-01-01T00:00:00Z to 2017-01-01T00:00:00Z
- Resolution docs-verified
- 3 arc-second (~90 m at the equator; pixel size 92.77 m)
- Formats docs-verified
- Earth Engine image (ee.Image)
- Access docs-verified
- Google Earth Engine account required (registration); dual licence: CC-BY-NC 4.0 or ODbL 1.0, user chooses which applies
Useful for
- Use cases llm-inferred
- Catchment area and upstream drainage screening at ungauged FRA sites · HAND-based screening of flood-prone land for drainage or flood risk assessments · River channel width and network mapping for watercourse baselines · Flow direction and drainage basin delineation for catchment-scale surface water assessments
- Audience llm-inferred
- flood consultants · hydrologists · drainage engineers · GIS analysts · environmental consultants
Limitations
- Constraints docs-verified
- Channel bifurcations not well represented (one downstream direction per pixel) · River width for braided/anabranching channels calculated per channel, not merged · Water body inconsistencies with DEM land-sea mask (e.g. new islands along coast); OpenStreetMap water layer quality not uniform · Underground rivers/tunnels not implemented · Below-sea-level coastal areas poorly represented · Flow direction over glaciers poorly represented · Uncertain watershed boundaries in arid basins with depressions · Requires Earth Engine access · ODbL: derived data used for commercial services must be published under ODbL · Developer may request co-authorship for additional handling/editing or outcomes highly dependent on the product
Evidence
- ee.Image('MERIT/Hydro/v1_0_1')
- https://developers.google.com/earth-engine/datasets/catalog/MERIT_Hydro_v1_0_1
Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.