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Flow direction from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database -- North America

Metadata Updated: January 19, 2026

This dataset contains the Flow Direction (FD) for North America from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The flow direction data were developed and distributed by processing units. There are 13 processing units for North America. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. na_fd_3_2.zip contains the flow direction data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date January 12, 2026
Metadata Updated Date January 19, 2026

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date January 12, 2026
Metadata Updated Date January 19, 2026
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/USGS_591b543be4b0a7fdb43c8d27
Data Last Modified 2020-08-14T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Datagov Dedupe Retained 20260119171902
Harvest Object Id b2bbf6c6-790c-4063-b3ed-68673c7dfe14
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial {"type": "Polygon", "coordinates": -179.147916666, 7.1100000001, -179.147916666, 83.1373611108, -52.6183333337, 83.1373611108, -52.6183333337, 7.1100000001, -179.147916666, 7.1100000001}
Source Datajson Identifier True
Source Hash 2538399153f1ddb856f5deb5c7679de8f3c739c2ce7e5ecaf1be9a2eeb42853d
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -179.147916666, 7.1100000001, -179.147916666, 83.1373611108, -52.6183333337, 83.1373611108, -52.6183333337, 7.1100000001, -179.147916666, 7.1100000001}

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