The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2020) is a dataset of hydrographic features and spatial data designed for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. These datasets are found as child items to this landing page: 1) Data Layers for the Geospatial Fabric for National Hydrologic Modeling, Alaska Domain, 2) GIS (Geographic Information Systems) Features of the Geospatial Fabric for National Hydrologic Modeling, Alaska Domain, 3) Parameter Database for the National Hydrologic Modeling, Alaska Domain, and 4) Topographic derivative datasets for the Geospatial Fabric for National Hydrologic Modeling, Alaska Domain. See each item for more details.

The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2021) is a dataset of hydrographic features and spatial data for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. The National Hydrologic Model database contains parameters for hydrologic response units (HRUs) and stream segments needed to run the NHM. These parameters are generated using python scripts to process input datasets such as digital elevation models, soil maps, and land cover classifications. Many of the parameters were left at their default model value as they would need to be calibrated as part of the PRMS model development process. Please refer to the Supplemental Information and the Process Description elements of this metadata record for more details on the source datasets and scripts used to generate these parameters.

The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2020) is a dataset of hydrographic features and spatial data designed for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. This child item contains data and information related to the GIS features of the Geospatial Fabric for National Hydrologic Model, Alaska domain. Two Open Geospatial Consortium geopackages are provided: one containing source layers that have had some pre-processing done from their native data formats (Reference_19.gpkg), and one (NHM_19.gpkg) containing 4 final feature layers for the NHM: points of interest (pois), a stream network (nsegment), aggregated catchments (catchments), and hydrologic response units (nhru). Features were derived from the MERRIT Hydro Global Hydrography Dataset.

The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2020) is a dataset of hydrographic features and spatial data designed for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. This child item contains data and information related to the GIS features of the Geospatial Fabric for National Hydrologic Model, Alaska domain. Two Open Geospatial Consortium geopackages are provided: one containing source layers that have had some pre-processing done from their native data formats (Reference_19.gpkg), and one (NHM_19.gpkg) containing 4 final feature layers for the NHM: points of interest (pois), a stream network (nsegment), aggregated catchments (catchments), and hydrologic response units (nhru). Features were derived from the MERRIT Hydro Global Hydrography Dataset.

This metadata record documents a geospatial dataset for the U.S. Geological Survey Precipitation Runoff Modeling System (PRMS) used to drive the National Hydrologic Model (NHM). The Alaska Geospatial Fabric v1 is the spatial representation of the hydrologic response units (HRUs) used for the PRMS NHM Alaska domain. These HRUs were generated using the twelve-digit Hydrologic Unit Code (HUC12) watershed from the U.S. Geological Survey's Watershed Boundary Dataset (USGS, 2019), the Natural Resources Canada National Hydrographic Network (NHN) Work Units (NHN, 2019), similar to USGS eight-digit HUC watersheds, and stream gage locations from the U.S. Geological Survey (USGS, 2019) and Natural Resources Canada (NHN, 2019). Watershed-to-watershed routing was added to all Canadian Work Units and updated in twelve-digit HUCs from topographic map examination to ensure connectivity from the headwaters of the domain to the ocean. Watersheds containing one or more stream gages were bisected using standard watershed delineation techniques to ensure accurate contributing area for each gage. Gages near watershed boundaries were not used to bisect the watershed. Following these processing steps, these watersheds became the HRUs used for the initial version of the National Hydrologic Model Alaska Domain. Overlapping watershed vector lines were not unified. The stream gages used for this exercise became the points of interest (POIs) for use in the Alaska Domain. Stream segments used to route water from HRUs to stream outlets were generated using the routing information in the HRUs and the centroids of the HRUs. Please refer to the lineage elements of this metadata record for the above citations.

This metadata record documents a geospatial dataset for the U.S. Geological Survey Precipitation Runoff Modeling System (PRMS) used to drive the National Hydrologic Model (NHM). The Alaska Geospatial Fabric v1 is the spatial representation of the hydrologic response units (HRUs) used for the PRMS NHM Alaska domain. These HRUs were generated using the twelve-digit Hydrologic Unit Code (HUC12) watershed from the U.S. Geological Survey's Watershed Boundary Dataset (USGS, 2019), the Natural Resources Canada National Hydrographic Network (NHN) Work Units (NHN, 2019), similar to USGS eight-digit HUC watersheds, and stream gage locations from the U.S. Geological Survey (USGS, 2019) and Natural Resources Canada (NHN, 2019). Watershed-to-watershed routing was added to all Canadian Work Units and updated in twelve-digit HUCs from topographic map examination to ensure connectivity from the headwaters of the domain to the ocean. Watersheds containing one or more stream gages were bisected using standard watershed delineation techniques to ensure accurate contributing area for each gage. Gages near watershed boundaries were not used to bisect the watershed. Following these processing steps, these watersheds became the HRUs used for the initial version of the National Hydrologic Model Alaska Domain. Overlapping watershed vector lines were not unified. The stream gages used for this exercise became the points of interest (POIs) for use in the Alaska Domain. Stream segments used to route water from HRUs to stream outlets were generated using the routing information in the HRUs and the centroids of the HRUs. Please refer to the lineage elements of this metadata record for the above citations.

This U.S. Geological Survey (USGS) data release consists of two hydrographic datasets with spatial modeling units, two sets of spatial data consistent with the National Hydrologic Model (NHM) Geospatial Fabric for National Hydrologic Modeling (abbreviated within this document as GFv1, Viger and Bock, 2014), and a database of 118 parameters used to run the NHM . These datasets are found as subpages to this landing page as 1) the GIS (geographic information system) features of the United States-Canada Transboundary Geospatial Fabric (TGF, added 08/04/2020), 2) the GIS features of the Geospatial Fabric v1.1 (GFv1.1 or v1_1, added 08/04/2020) which is an update to the GF and includes the TGF, 3) Topographic derivative datasets for the United States-Canada transboundary Geospatial Fabric (added 10/28/2020), 4) Data Layers for the National Hydrologic Model, version 1.1, and 5) National Hydrologic Model's United States-Canada Transboundary Geospatial Fabric Parameter Database (added 11/10/2021). See subpages for more details.

This U.S. Geological Survey (USGS) data release consists of two hydrographic datasets with spatial modeling units, two sets of spatial data consistent with the National Hydrologic Model (NHM) Geospatial Fabric for National Hydrologic Modeling (abbreviated within this document as GFv1, Viger and Bock, 2014), and a database of 118 parameters used to run the NHM . These datasets are found as subpages to this landing page as 1) the GIS (geographic information system) features of the United States-Canada Transboundary Geospatial Fabric (TGF, added 08/04/2020), 2) the GIS features of the Geospatial Fabric v1.1 (GFv1.1 or v1_1, added 08/04/2020) which is an update to the GF and includes the TGF, 3) Topographic derivative datasets for the United States-Canada transboundary Geospatial Fabric (added 10/28/2020), 4) Data Layers for the National Hydrologic Model, version 1.1, and 5) National Hydrologic Model's United States-Canada Transboundary Geospatial Fabric Parameter Database (added 11/10/2021). See subpages for more details.

The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2020) is a dataset of hydrographic features and spatial data designed for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. This child item consists of topographic data themes that cover the Geospatial Fabric for National Hydrologic Modeling, Alaska Domain. The 30-meter (m) raster datasets included under Topographic Derivatives are: digital elevation (dem.tif), topographic wetness index (TWI, twiX100.tif), slope (rise over run, slope.tif), aspect (asp.tif), flow accumulation (fac.tif), and flow direction (fdr.tif). All file formats are in GeoTIFF (Geographic Tagged Imaged Format), and are sourced from NHDPlus Version 2.0 raster layers (Environmental Protection Agency, 2019)

The Geospatial Fabric for National Hydrologic Modeling (Viger and Bock, 2014; Bock and others, 2020) is a dataset of hydrographic features and spatial data designed for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Hawaii, and most major river basins that flow in from Canada. This U.S. Geological Survey (USGS) data release consists of the geospatial fabric features and other related spatial datasets created to expand the National Hydrologic Model to Alaska. This child item consists of topographic data themes that cover the Geospatial Fabric for National Hydrologic Modeling, Alaska Domain. The 30-meter (m) raster datasets included under Topographic Derivatives are: digital elevation (dem.tif), topographic wetness index (TWI, twiX100.tif), slope (rise over run, slope.tif), aspect (asp.tif), flow accumulation (fac.tif), and flow direction (fdr.tif). All file formats are in GeoTIFF (Geographic Tagged Imaged Format), and are sourced from NHDPlus Version 2.0 raster layers (Environmental Protection Agency, 2019)