SWORD: A Global River Network for SWOT Satellite Data

SWORD (SWOT River Database) is a global vector database of river nodes and reaches designed for the Surface Water and Ocean Topography (SWOT) satellite mission. It provides high-resolution river nodes (200 m) and reaches (~10 km) in shapefile and NetCDF formats with attached hydrologic variables like water surface elevation, width, and slope. The database defines a consistent topological system for global rivers 30 meters wide and greater to enable multitemporal analysis of SWOT data products.

Use Cases

• Assigning SWOT satellite overpass data to predefined river reaches and nodes for consistent time-series analysis.
• Analyzing river hydrology (e.g., water surface elevation, width, slope) using the attached variables at node and reach scales.
• Conducting global or continental-scale river network analysis based on the provided topological system and continent-specific files.
• Preparing discharge calculations using the 'filler' variables included in the project version NetCDF files.

Strengths

• Provides a global, high-resolution topological network for rivers, with nodes at 200 m and reaches at ~10 km intervals.
• Integrates multiple global river and satellite datasets to define a priori reaches for the SWOT mission, ensuring consistency for multitemporal analysis.
• Offers data in both shapefile and NetCDF formats, structured with continent-specific identifiers (e.g., 'af' for Africa, 'as' for Asia).
• Is publicly available with a clear citation (Altenau et al., 2021) and an online explorer (swordexplorer.com).

Limitations

• Key metadata such as row count, file size, and specific column names are not provided in the available sources.
• The dataset's update history and the exact 'last updated' date are unclear from the provided metadata.
• There is a noted version history where project and public versions were separate, and version numbers jumped after v2, which may require users to reference documentation for details.

Provenance

Source

Created by Elizabeth H. Altenau, associated with the University of North Carolina at Chapel Hill, for the SWOT mission.

Collection Method

Combines multiple global river- and satellite-related datasets, including GRWL 30 m centerlines, to define nodes and reaches.

Geography

Global coverage, with data files organized by continent (Africa, Asia/Siberia, Europe/Middle East, North America, Oceania, South America).