{BA1041E9-02B6-40ED-8DB0-B1EEF68B6CA7} eng; USA utf8 dataset EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact 2025-02-11 ISO 19115 Geographic Information - Metadata ISO 19115:2003/Cor.1:2006(E) EnviroAtlas - NHDPlus V2 WBD Snapshot, EnviroAtlas version - Conterminous United States 2015-02-02 publication U.S. EPA Office of Research & Development (ORD) - National Exposure Research Laboratory (NERL) Research Triangle Park NC publisher US Environmental Protection Agency (US EPA) originator This EnviroAtlas dataset is a digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the conterminous United States, based on the January 6, 2015 NHDPlus V2 WBD (Watershed Boundary Dataset) Snapshot (NHDPlusV21_NationalData_WBDSnapshot_FileGDB_05). The feature class has been edited for use in for EPA ORD's EnviroAtlas. Features in Canada and Mexico have been removed, the boundaries of three 12-digit HUCs have been edited to eliminate gaps and overlaps, the dataset has been dissolved on HUC_12 to create multipart polygons, and information on the percent land area has been added. Hawaii, Puerto Rico, and the U.S. Virgin Islands have been removed, and can be downloaded separately. Other than these modifications, the dataset is the same as the WBD Snapshot included in NHDPlus V2. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets). The purpose of this EnviroAtlas dataset is to provide a consistent set of 12-digit HUCs for EnviroAtlas national datasets. The overall goal of EnviroAtlas is to employ and develop the best available science to map indicators of ecosystem services production, demand, and drivers for the nation. completed EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact asNeeded Ecosystem Environment theme EPA GIS Keyword Thesaurus 12-digit HUCs Boundaries Ecosystem Services EnviroAtlas Environment Environmental Atlas theme EnviroAtlas Alabama Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas United States Utah Vermont Virginia Washington Washington DC West Virginia Wisconsin Wyoming place None https://edg.epa.gov/EPA_Data_License.htm otherRestrictions Use Constraints: None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated. otherRestrictions Access Constraints: None PUBLIC https://project-open-data.github.io/schema/#accessLevel Standard Technical Controls eng; USA environment -128.02839229 -65.20336449 22.7348894 51.6773602 2015-02-02 true Entity and Attribute Information Entity and Attribute Overview: For more information about EnviroAtlas data, go to https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets. This dataset is based on the January 6, 2015 NHDPlus V2 WBD Snapshot. HUCs completely in Canada or Mexico have been removed, HUCs crossing the US-Canada border have been split and portions in Canada have been removed. The boundaries of 3 HUCs have been adjusted to remove gaps and overlaps. The dataset has been dissolved on the field HUC_12 to create multipart polygons. The percent land area attribute was generated using the ATtILA tool (https://www.epa.gov/eco-research/analytical-tools-interface-landscape-assessments-attila-landscape-metrics), an ArcView tool for calculating commonly used landscape metrics, in conjunction with the 2011 National Land Cover Database (NLCD) (http://www.mrlc.gov/). For more information on the metric calculation, please see the ATtILA User's Manual (https://www.epa.gov/eco-research/analytical-tools-interface-landscape-assessments-user-manual). A comprehensive list of metric creation steps is included in the Processing Steps. Entity and Attribute Detail Citation: https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas distributor https://enviroatlas.epa.gov/download/NHDPlusV2_WBDSnapshot_EnviroAtlas_CONUS.gdb.zip download Download The URL providing direct access to the downloadable dataset. download https://enviroatlas.epa.gov/arcgis/rest/services/Other/HydrologicUnits/MapServer ESRI:ArcGIS API The endpoint of a web service to access the dataset (REST endpoint, WMS GetCapabilities URL, or a SOAP WSDL endpoint). webMapService https://www.epa.gov/enviroatlas/enviroatlas-data information Documentation URL for accessing related documents such as data dictionary, technical information about a dataset, developer documentation, etc. information https://www.epa.gov/enviroatlas information Home Page Alternative landing page used to redirect user to a contextual, Agency-hosted "homepage" for the Dataset or API information dataset Horizontal Positional Accuracy Report Data were collected using methods that have unknown accuracy (EPA National Geospatial Data Policy [NGDP] Accuracy Tier 10). For more information, please see EPA's NGDP at https://www.epa.gov/geospatial/geospatial-policies-and-standards Features represented have not been tested for completeness Features represented have not been tested for completeness Tests for integrity have not been performed. This lineage was generated by the FGDC CSDGM to 19139 transformation 1. Downloaded the NHDPlus V2 WBD Snapshot V5 (WBD) from www.horizon-systems.com/NHDPlus/NHDPlusV2_home.php. 2015-01-26T00:00:00 2. Eliminated gaps and overlapping areas between HUCs: 2015-01-26T00:00:00 2.a. Moved the boundary of 041504090000 to the east to align it with the boundary of 041503080406. I modified 041504090000 instead of 041503080406 since it was the later addition. 2015-01-26T00:00:00 2.b. Moved the southern boundary of 020600020401 south to close a gap and moved the southern boundary of 020402070101 north to eliminate an overlap, aligning both to 020600020402’s northern boundary. 2015-01-26T00:00:00 3. Validated the topology of the feature class. 2015-01-26T00:00:00 4. Exported and projected the WBD into USA_Contiguous_Albers_Equal_Area_Conic_USGS_version 2015-01-26T00:00:00 5. Removed features and parts of features that were outside US boundaries: 2015-01-26T00:00:00 5.a. Downloaded the International Boundary Commission (IBC) Canada / United States of America Boundary Dataset from http://www.internationalboundarycommission.org/coordinates/US_CAN_Boundary_v1.1.zip and then edited it to make it suitable for splitting the HUC polygons: 2015-01-26T00:00:00 5.a.i. Projected the shapefile into Albers. 2015-01-26T00:00:00 5.a.ii. Extended the boundary line at the West Coast until it passed the extents of the WBD using the Extend Line tool. 2015-01-26T00:00:00 5.a.iii. There is a boundary line in the Atlantic Ocean near the border with Maine that is not connected to the other lines. Connected the lines by adding a line between the two vertices. 2015-01-26T00:00:00 5.b. Used the Split Polygons tool to split the border HUCs along the US-Canada boundary. 2015-01-28T00:00:00 5.c. Deleted all HUCs that were entirely in Canada. Also deleted parts of HUCs that were split by the boundary line and fell on the Canadian side of the boundary. In some cases, HUCs that already roughly aligned with the boundaries were split due to an imperfect alignment between the HUC boundary and the IBC boundary, such as along the 49th parallel, creating very small slivers of the HUCs on the Canadian side of the boundary. In these cases, the original HUCs were left unchanged. 2015-01-28T00:00:00 6. Dissolved on HUC12 to join slivers along 49th parallel back into their original HUCs and to make all HUCs with more than one part into multipart polygons. 2015-01-28T00:00:00 7. Removed Hawaii, Puerto Rico, and the U.S. Virgin Island; they are available for download in a separate file geodatabase. 2015-01-28T00:00:00 8. Calculated the percent land area by HUC using the 2011 NLCD and the ATtILA tool: 2015-01-30T00:00:00 8.a. Calculate areas for water (NLCD classes 11 and 12), barren (31), forest (41, 42, 43), tundra (51, 72, 73, 74), shrubland (52), herbaceous (71), wetland (90, 95), developed (21, 22, 23, 24), and agriculture (81, 82). 2015-01-30T00:00:00 8.b. Summed land area (all classes other than water). 2015-01-30T00:00:00 8.c. Calculated % land area using LCP_TOTA, the total HUC12 area calculated by ATtILA, as the denominator: ( [LandArea] / [LCP_TOTA] ) * 100 2015-01-30T00:00:00 Source Contribution: 12-digit HUC SubwatershedsSource Type: online 24000 NHDPlus V2 National WBD Snapshot 2015-01-06 publication version 5 U.S. Deparment of Agriculture, Natural Resources Conservation Services Fort Worth TX publisher Natural Resources Conservation Services (NRCS) originator mapDigital 1980-01-01 2010-03-25 Source Contribution: Boundary data used to clip subwatershedsSource Type: online US-Canada Boundary 2014-07-18 publication 1.1 International Boundary Commission Washington DC publisher Canada / United States of America Boundary Dataset originator mapDigital 2014-07-18 Source Contribution: Land cover data used for calculating percent land areaSource Type: online NLCD 2011 Land Cover (2011 Edition, amended 2014) - National Geospatial Data Asset (NGDA) Land Use Land Cover 2014-10-10 publication 2011 U.S. Geological Survey Sioux Falls SD publisher U.S. Geological Survey originator imageDigital 2004-04-09 2011-11-11 unknown 2029-02-11 This metadata was automatically generated from the FGDC Content Standard for Digital Geospatial Metadata standard (version FGDC-STD-001-1998) using the 2024-02-09T11:11:00 version of the FGDC CSDGM to ISO 19139 transform. EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact