HydroSHEDS download and formats: raster hydrography, catchments, river networks, and GIS workflows

What HydroSHEDS contains

The core HydroSHEDS layers are gridded hydrographic foundations derived from elevation and hydrologic processing. They include a void-filled digital elevation model, a hydrologically conditioned elevation model, drainage-direction grids, flow-accumulation grids, flow-length grids, and a land mask identifying land, ocean sinks, and inland sinks. The flow-accumulation products can represent either the number of upstream grid cells or upstream area, depending on the layer and resolution. (hydrosheds.org)

The wider ecosystem adds vector layers derived from or aligned with these grids. HydroBASINS provides nested catchment and sub-basin polygons; HydroRIVERS provides river-reach lines; HydroLAKES provides lake polygons and pour points; and HydroATLAS adds hydro-environmental attributes to basin, river, and lake features. These products are designed to be spatially and hydrographically compatible, but they are not interchangeable: a flow-direction raster, a river centerline, and a basin polygon answer different geographic questions. (hydrosheds.org)

• •Core raster layers: DEM, conditioned DEM, flow direction, flow accumulation, flow length, and land mask.
• •Secondary vector layers: HydroBASINS, HydroRIVERS, and HydroLAKES.
• •Associated and attribute-rich products: HydroATLAS and other HydroSHEDS-related datasets.

Geography, versions, and update cadence

HydroSHEDS v1 was derived primarily from the SRTM digital elevation model at 3 arc-seconds, approximately 90 meters at the equator, with custom hydrologic processing. Because SRTM coverage does not extend above 60 degrees north, v1 products in much of the Arctic use the coarser HYDRO1k elevation model or are unavailable at the highest resolution. This creates an important regional quality difference that should be documented in analyses spanning northern latitudes. (hydrosheds.org)

HydroSHEDS v2 is the newer generation, based on TanDEM-X elevation data and produced at 1 arc-second, approximately 30 meters at the equator. The first released v2 core data cover North, Central, and South America and include raster products plus vector river-network and basin-related data. The project describes v2 as an ongoing global development effort, so users should not assume that a v2 download represents complete worldwide coverage. (hydrosheds.org)

• •v1.1: mature global framework, with known high-latitude limitations inherited from SRTM availability.
• •v2: newer TanDEM-X-based products, initially released for the Americas at approximately 30 meters.
• •Update cadence: no fixed project-wide schedule is published; treat releases as versioned snapshots.

Download options and file formats

The current HydroSHEDS v1.1 core download page distributes raster layers in GeoTIFF format. Available resolutions include 3, 15, and 30 arc-seconds and 5 and 6 arc-minutes, with continental, global, or tiled downloads depending on the layer and resolution. The highest-resolution rasters are commonly distributed as 10-by-10-degree tiles or continental composites. File names encode information such as geographic extent, layer type, and resolution, which is useful when automating downloads and building reproducible processing pipelines. (hydrosheds.org)

The legacy archive contains v1.0 data in BIL, GRID, and Shapefile formats. HydroSHEDS explicitly identifies those files as obsolete and recommends GeoTIFF v1.1 unless a legacy application requires the older formats. HydroSHEDS v2 downloads use GeoTIFF for core raster layers, while released vector data are available as zipped Esri File Geodatabases and OGC GeoPackages. (hydrosheds.org)

• •Preferred current v1.1 raster format: GeoTIFF.
• •Legacy v1.0 formats: BIL, GRID, and older Shapefile products.
• •v2 core rasters: GeoTIFF; released vectors include File Geodatabase and GeoPackage.
• •Access methods: official download pages, tiled or continental archives, and selected external computational platforms with verification required.

Suitable GIS and spatial-analysis workflows

A common raster workflow begins by selecting a resolution appropriate to the analysis, downloading the same version and extent for DEM, conditioned DEM, flow direction, and flow accumulation, and checking coordinate reference system, NoData values, data type, tile boundaries, and naming conventions. Tiles can then be mosaicked, clipped to a study area, or reprojected for analysis. For hydrologic modeling, the conditioned DEM and flow-direction grid are more relevant than the unconditioned elevation surface because they encode the project’s drainage assumptions.

For basin-based analysis, HydroBASINS can provide a ready-made polygon hierarchy for spatial joins and aggregation. Analysts can assign roads, buildings, environmental observations, permits, or other features to level-specific sub-basins, then summarize counts, areas, or indicators by watershed. HydroRIVERS and HydroLAKES are useful for proximity calculations, map overlays, network-aware interpretation, and linking places to named or indexed water features where supplementary naming data is available. HydroATLAS is appropriate when the analysis needs precomputed hydro-environmental attributes rather than geometry alone.

• •Raster preprocessing: inspect metadata, mosaic compatible tiles, preserve NoData, and avoid mixing versions or resolutions without documenting resampling.
• •Vector analysis: spatially join points, lines, and polygons to HydroBASINS levels; calculate distance or intersection with HydroRIVERS and HydroLAKES.
• •Regional comparison: aggregate physical-world features by catchment, upstream area, flow-accumulation class, or river hierarchy.
• •Validation: compare important outputs with local hydrography, engineering datasets, observed water levels, or current Earth-observation products.

License, strengths, and tradeoffs

The core v1 products are freely available for scientific, educational, and commercial use, but the official documentation and license agreement govern attribution, redistribution, warranties, liability, and other conditions. HydroSHEDS states that licenses differ across product families because products use different source data and collaborations. Users should therefore read the product-specific terms rather than applying the v1 core license to HydroLAKES, HydroATLAS, or another related dataset automatically. (hydrosheds.org)

• •Strength: globally consistent hydrographic structure that supports cross-border watershed and river analysis.
• •Strength: coordinated raster and vector products with multiple resolutions and nested basin levels.
• •Strength: practical interoperability through GeoTIFF and common GIS vector formats.
• •Tradeoff: v1 has weaker or missing highest-resolution coverage above 60 degrees north.
• •Tradeoff: version coverage and update timing are uneven, especially during the transition to v2.
• •Tradeoff: terrain-derived and generalized hydrography should not be treated as current local engineering, cadastral, flood-hazard, or streamflow observations.