HydroSHEDS v2 is the next generation of global hydrographic data, providing a seamless, high-resolution foundation for mapping and analyzing freshwater systems worldwide. The HydroSHEDS v2 database are a suite of gridded and vector datasets derived from TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) elevation data.

DLR processed the original 12 m resolution TanDEM-X data to create a hydrologically pre-conditioned DEM that was further refined by hydrological optimisation and correction algorithms by Confluvio Consulting Inc., Montreal, Que., Canada, to derive drainage pathways. The resulting HydroSHEDS v2 database will provide river networks and catchment boundaries at full global coverage. See https://www.hydrosheds.org/hydrosheds-v2 for more information.

The core data products of HydroSHEDS v2 are freely available and are provided at a resolution of 1 arc-second (~30 meters at the equator):

• Flow Directions (DIR): A drainage direction map derived from the conditioned elevation data - Flow Accumulation (ACC): A flow accumulation map derived from the flow direction map, representing the number of upstream grid cells
• River network (RIV): A river network derived from the flow direction map, using a minimum upstream catchment threshold of 1 square kilometers
• HydroBASINS (BAS): A beta version of drainage basins (HydroBASINS) as a companion layer for the river reaches. The data is currently limited to the Americas. Additional regions will be made available in future releases.