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.

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.

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 is a dataset of spatial modeling units for use within the National Hydrologic Model that covers Alaska, 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 datasets created to expand the National Hydrologic Model to Alaska. This U.S. Geological Survey (USGS) child item consists of 17 different spatial layers in GeoTIFF format for Alaska. They are 1) average water capacity (awc.zip), 2) percent sand (sand.zip), 3) percent silt (silt.zip), 4) percent clay (clay.zip), 5) soil texture (TEXT_PRMS.zip), 6) land use/land cover (LULC.zip), 7) snow values (snow.zip), 8) summer rain values (SRain.zip), 9) winter rain values (WRain.zip), 10) leaf presence values (keep.zip), 11) leaf loss values (loss.zip), 12) percent tree canopy (CNPY.zip), 13) percent impervious surface (imperv.zip), 14) snow depletion curve numbers (CV_INT.zip), 15) rooting depth (RootDepth.zip), 16) permeability values (Lithology_exp_Konly_Project.zip), and 17) water bodies (wbg.zip). All data cover the National Hydrologic Model's (NHM) Alaskan domain. The 250-meter (m) raster datasets for soils (in sand.zip, silt.zip, clay.zip, TEXT_PRMS.zip) are derived from the Zonodo data (Hengl, 2018). The 30-meter raster of land use and land cover data are a simplified re-classification version of the North American Land-Change Monitoring System (NALCMS, Latifovic and others, 2012) data following the guidance and crosswalk table (crosswalk.csv) in Viger and Leavesley (2007). This layer was used to derive rasters representing dominant vegetative cover type, snow, summer and winter rain interception values, leaf cover and loss, and rooting depth. The impervious data were compiled from the Global Man-made Impervious Surface (GMIS) Dataset from Landsat, v1 (Brown de Colstoun, 2010). The tree canopy data were compiled from MOD44B MODIS/Terra Vegetation Continuous Fields Yearly L3 Global 250m SIN Grid V006, (Sexton and others, 2013). The snow depletion data was compiled from data by Liston (2009) and further processed using methods provided in a snow depletion table (SDC_table.csv) by Sexstone and others (2020). All file formats are in GeoTIFF (Geograhpic Tagged Imaged Format).

The Geospatial Fabric is a dataset of spatial modeling units for use within the National Hydrologic Model that covers the conterminous United States (CONUS), Alaska, 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 datasets created to expand the National Hydrologic Model to Hawaii. These datasets are found as child items to this landing page: 1) Data Layers for the Geospatial Fabric for National Hydrologic Modeling, Hawaii Domain, 2) GIS (Geographic Information Systems) Features of the Geospatial Fabric for National Hydrologic Modeling, Hawaii Domain, 3) Parameter Database for the National Hydrologic Modeling, Hawaii Domain, and 4) Topographic derivative datasets for the Geospatial Fabric for National Hydrologic Modeling, Hawaii Domain. See each item for more details.

The Geospatial Fabric version 1.1 (GFv1.1 or v1_1) is a dataset of spatial modeling units covering the conterminous United States (CONUS) and most major river basins that flow in from Canada. The GFv1.1 is an update to the original Geospatial Fabric (GFv1, Viger and Bock, 2014) for the National Hydrologic Modeling (NHM). Analogous to the GFv1, the GFv1.1 described here includes the following vector feature classes: points of interest (POIs_v1_1), a stream network (nsegment_v1_1), and hydrologic response units (nhru_v1_1), with several additional ancillary tables. These data are contained within the Environmental Systems Research Institute (ESRI) geodatabase format (GFv1.1.gdb).

The Geopspatial Fabric provides a consistent, documented, and topologically connected set of spatial features that create an abstracted stream/basin network of features useful for hydrologic modeling.The GIS vector features contained in this Geospatial Fabric (GF) data set cover the lower 48 U.S. states, Hawaii, and Puerto Rico. Four GIS feature classes are provided for each Region: 1) the Region outline ("one"), 2) Points of Interest ("POIs"), 3) a routing network ("nsegment"), and 4) Hydrologic Response Units ("nhru"). A graphic showing the boundaries for all Regions is provided at http://dx.doi.org/doi:10.5066/F7542KMD. These Regions are identical to those used to organize the NHDPlus v.1 dataset (US EPA and US Geological Survey, 2005). Although the GF Feature data set has been derived from NHDPlus v.1, it is an entirely new data set that has been designed to generically support regional and national scale applications of hydrologic models. Definition of each type of feature class and its derivation is provided within the section of this metadata document. The first entry in that section provides an overview of the delineation process, with each subsequent corresponding to one of the four types of feature. These entries describe the derivation of feature types in the order in which they are created. Minimal attribution (feature size, location, and routing connectivity) is provided for the feature classes within the GF Feature data set. More extensive feature attribution is published separately as individual tables of attributes(for example, http://dx.doi.org/doi:10.5066/F7RX9937) or via entire configurations of tables engineered to satisfy particular watershed models (for example, http://dx.doi.org/doi:10.5066/F7WM1BF7).