GRIT: Global River Topology Network at 30m Resolution

GRIT is a vector-based global river network representing tributary and distributary components, including multi-thread rivers, canals, and delta distributaries. It is the first global hydrography excluding Antarctica and Greenland produced at 30m raster resolution, created by merging Landsat-based river masks with elevation-generated streams. The dataset was authored by Michel Wortmann of the University of Oxford and is available as GeoPackage files.

Use Cases

• Model river flow direction and connectivity based on the assigned upstream/downstream node IDs and segment topology.
• Analyze river network structure and bifurcation patterns using the is_mainstem and cycle attributes.
• Subset data for regional hydrological studies using the provided 60 subcontinental catchment group attributes.
• Assess river sinuosity and channel geometry based on the length, azimuth, and sinuous ratio attributes.

Strengths

• Provides a global river network at 30m resolution, a first for hydrography excluding Antarctica and Greenland.
• Uses the FABDEM 30m digital terrain model, which the description states shows greater accuracy than traditional SRTM derivatives.
• Includes both tributary and distributary network components, such as multi-thread rivers and delta distributaries.
• Offers detailed topological attributes like upstream/downstream IDs and segment connectivity for graph-based analysis.

Limitations

• Row count and total file size are unknown, which may limit suitability assessment for large-scale processing.
• Last update date is unknown; freshness unverified.
• Excludes coverage of Antarctica and Greenland.

Provenance

Source

University of Oxford (Michel Wortmann)

Collection Method

Created by merging Landsat-based river mask (GRWL) with elevation-generated streams, vectorized and assigned directionality using a combination of elevation, flow angle, heuristic, and continuity approaches (based on RivGraph).

Geography

Global (excluding Antarctica and Greenland), divided into 6 continental regions and 60 subcontinental catchment groups.