Reference: Lane and D'Amico 2016U.S. EPAAttributesFeature Class87653OBJECTIDInternal feature number.ESRIPolygon2-dimensional element.ESRI GIS softwareSequential unique whole numbers that are automatically generated.OBJECTIDOID400Final_IDUnique identifier for each wetland complex. Links to NWI_Attribute table and Wetland Class Summed table.U.S. EPAUnique IdentifierUnique Identifier used to track wetlands defined by U.S. EPAFinal_IDString2000AdjBufferNULL; Indicates whether a polygon is adjacent or overlapping a 10- meter buffer of select NHD data.U.S. EPAYes - Adjacent to buffer, NULL– not adjacentAdjBufferString500AdjRiverineNULL; Indicates whether a polygon is adjacent or overlapping a riverine wetland from the NWI.U.S. EPAYes - Adjacent to riverine wetland, NULL– not adjacentAdjRiverineString500IsolatedIndicates if a wetland is geographically isolated – all polygons in this data layer will have a yes.U.S. EPAyes – wetland is isolated, NULL or No – not isolatedIsolatedString500ShapeFeature geometry.EsriCoordinates defining the features.ShapeGeometry000InStateIndicates what State the wetland is either fully or predominately withinU.S. EPAShows abbreviation of state that the polygon is mostly within.InStateString500Shape_LengthLength of feature in internal units.EsriPositive real numbers that are automatically generated.Shape_LengthDouble800AcresTotal acres of geographical isolated wetland.U.S. EPAAcresAcres calculated by U.S. EPA in ArcGIS using the field calculator in AlbersAcresDouble800hectaresTotal hectares of geographical isolated wetlandU.S. EPAHectaresHectares calculated by U.S. EPA in ArcGIS in Albers.hectaresDouble800Shape_AreaArea of feature in internal units squared.EsriPositive real numbers that are automatically generated.Shape_AreaDouble800Geographically Isolated Wetlands (Non-Floodplain Wetlands) 698419.5500001044237.360000826619.2725001375928.8900001002ProjectedGCS_North_American_1983Linear Unit: Meter (1.000000)NAD_1983_Albers<ProjectedCoordinateSystem xsi:type='typens:ProjectedCoordinateSystem' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:typens='http://www.esri.com/schemas/ArcGIS/10.3'><WKT>PROJCS["NAD_1983_Albers",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Albers"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-96.0],PARAMETER["Standard_Parallel_1",29.5],PARAMETER["Standard_Parallel_2",45.5],PARAMETER["Latitude_Of_Origin",23.0],UNIT["Meter",1.0]]</WKT><XOrigin>-16901100</XOrigin><YOrigin>-6972200</YOrigin><XYScale>10000</XYScale><ZOrigin>-100000</ZOrigin><ZScale>10000</ZScale><MOrigin>-100000</MOrigin><MScale>10000</MScale><XYTolerance>0.001</XYTolerance><ZTolerance>0.001</ZTolerance><MTolerance>0.001</MTolerance><HighPrecision>true</HighPrecision></ProjectedCoordinateSystem>201603281332590020240228135130001.01500000005000ISO19115_3Charles LaneU.S. EPA, Office of Research and Development 706-355-8235 980 College Station RoadAtlantaGA30605lane.charles@epa.gov2024-02-28ArcGIS Metadata1.0Geographically Isolated Wetlands (Non-Floodplain Wetlands) of the Conterminous United States 2016-01-29U.S. EPA, Office of Research and DevelopmentCharles Lanevector digital dataThis data set represents the extent and approximate location of GIWs, also known as non-floodplain wetlands (NFWs), in the conterminous United States. NWI lacustrine systems and palustrine wetlands were determined to be “isolated” based on their geographic location (i.e., unconnected, based on a distance measure, to specific classes of NHD aquatic systems). GIWs were here considered geographically isolated when they were outside of 10 meters from select NHD lines and polygons or were not adjacent to NWI Riverine or Estuarine wetlands and (where applicable) outside of 10 meters from a coastline (e.g., oceans or Great Lakes).Mapping the extent of potential geographically isolated wetlands (also known as non-floodplain wetlands) is a first step towards better understanding the functioning of these systems. A map of geographically isolated wetlands (GIWs) in the conterminous U.S. significantly aids in the ability to understand the impacts and effects of various regulations, guidance, and management strategies on the resource. Using the National Wetlands Inventory (NWI) and National Hydrography Dataset (NHD) data layers, we quantified the abundance and spatial extent of potential GIWs across the conterminous United States. We maintained the convention of defining geographically isolated wetland systems as those completely surrounded by uplands, while acknowledging that this construct, like most definitions in ecology, incompletely bounds a connectivity and/or isolation gradient. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the development of this dataset under contract EP-D-11-073 to CSS-Dynamac. This dataset has been subjected to Agency review and approved for publication, but does not necessarily reflect the views and policies of the United States Environmental Protection Agency. Preferred Citation: Lane, C., and D’Amico, E: Geographically Isolated Wetlands (Non-Floodplain Wetlands) of the Conterminous United States [dataset], https://doi.org/10.1111/1752-1688.12421, 2016.
U.S. Fish & Wildlife (NWI); USGS (NHD)
Identification of Putative Geographically Isolated Wetlands of the Conterminous United States, CR Lane, E D'Amico. JAWRA Journal of the American Water Resources Association 52 (3), 705-722 https://doi.org/10.1111/1752-1688.12421
Use limitations
EPA Place Names2015-01-31https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/taxonomies/search.do?search=&searchString=&taxonomyName=WBT%20-%20Geographic%20LocationsWeb Taxonomy - Geographic LocationsAlabama, Arkansas, Arizona, California, Colorado, Connecticut, District of Columbia, Delaware, Florida, Georgia, Iowa, Indiana, Illinois, Idaho, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Minnesota, Michigan, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, New Mexico, Nevada, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Vermont, Washington, Wisconsin, West Virginia, Wyoming, United StatesISO 19115 Topic Categories2023-07-28T00:00:00environmentEPA GIS Keyword Thesaurus2007-11-02https://www.epa.gov/geospatial/epa-metadata-technical-specificationEPA Metadata Technical SpecificationEnvironmentWaterenvironmentinland watersAlabamaArkansasArizonaCaliforniaColoradoConnecticutDistrict of ColumbiaDelawareFloridaGeorgiaIowaIndianaIllinoisIdahoKansasKentuckyLouisianaMassachusettsMarylandMaineMinnesotaMichiganMissouriMississippiMontanaNorth CarolinaNorth DakotaNebraskaNew HampshireNew JerseyNew MexicoNevadaNew YorkOhioOklahomaOregonPennsylvaniaRhode IslandSouth CarolinaSouth DakotaTennesseeTexasUtahVirginiaVermontWashingtonWisconsinWest VirginiaWyomingconterminous U.S.environment; non-floodplainswetlandsconnectivityMicrosoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.1.4959-127.853934-65.34819522.98501651.6012412013-01-01T00:00:00Temporal extents reflect the time period of input datasetsConterminous United States2013-01-012015-12-31EPA Value-AddedThere are no access and use limitations for this item. Please check sources, scale, accuracy, currentness and other available information. Please confirm that you are using the most recent copy of both data and metadata.Charles LaneU.S. EPA Office of Research and Developmentlane.charles@epa.gov960 College Station RoadAthensGA30605706-355-8235 Charles Lane[My Contacts] Charles Lane[From Metadata Record] Charles Lane[From Metadata Record] Charles LaneCharles Lane-127.853934-65.34819551.60124122.985016Federal Program Inventory2013-09-16https://resources.data.gov/schemas/dcat-us/v1.1/FederalProgramInventory_FY13_MachineReadable_091613.csvFederal Program Inventory020:072NoneNoneEPA Public Domain License
Access constraints - unrestricted license 87653https://dmap-prod-oms-edc.s3.us-east-1.amazonaws.com/ORD/CONUS_NFWs/Geographically_Isolated_Wetlands_of_ConterminousUnitedStates.gdb.zipdatasetSimpleFALSE87653TRUEFALSEMethodology for producing non-floodplain wetlandsOrigin: U.S. Fish and Wildlife Service
Title: Wetlands and Deepwater Habitats of the Conterminous United States: National Wetland Inventory
Published by: U.S. Fish and Wildlife Service
Published at: Washington, D.C.
Date: 1977 to present
Wetlands and Deepwater Habitats of the Conterminous United States2016-04-05T00:00:00Origin: U.S. Geological Survey in cooperation with U.S. Environmental Protection Agency, USDA Forest Service, and other Federal, State and local partners
Title: National Hydrography Dataset
Published by: U.S. Geological Survey
Published at: Reston, Virginia
Date: 2013-03-07
National Hydrography Dataset2016-04-05T00:00:00For each state, the polygons delineated as geographically isolated as well as the attribute table from the riverine and lacustrine non-aggregated dataset were exported into a single geodatabase. An additional table that summarizes the wetland class for each aggregated polygon was also created. Both the tables and the polygons are linked by the Final_ID field.2016-04-22T00:00:00Ellen D'AmicoPegasus Technical Services c/o U.S. EPAdamico.ellen@epa.gov26 W. Martin Luther King Dr.Cincinnati OH45268(513) 569-7167Ellen D'AmicoEllen D'AmicoEllen D'AmicoFor each state, the NWI was split into two data layers: Palustrine and Lacustrine wetlands and Riverine and Estuarine wetlands. Riverine and Estuarine wetlands are intrinsically connected wetlands and therefore cannot be potentially isolated. The Palustrine and Lacustrine wetlands were converted to single part polygons, allowing verification that each polygon in the data layer was geographically distinct. Due to the presence of “true arcs” in the NWI, the polygons were densified prior to analysis. 2016-04-22T00:00:00Ellen D'AmicoPegasus Technical Services c/o U.S. EPAdamico.ellen@epa.gov26 W. Martin Luther King Dr.Cincinnati OH45268(513) 569-7167Ellen D'AmicoEllen D'AmicoEllen D'AmicoFor ND, SD, IA, NE, MT, and MN:
The Palustrine and Lacustrine wetlands were aggregated using the Aggregate Polygon route available in ArcGIS. The states were broken down into subareas, aggregated, then remerged back together. A unique id called Final_ID was added. The Final_ID links the non-aggregated polygons with the aggregated polygons and with the original NWI attribute table.
For all other states:
The Palustrine and Lacustrine wetlands were aggregated using a combination of an ArcGIS tool called Polygon Neighbors and an EPA in-house developed Python script. The Polygon Neighbors tool builds a table that shows which polygons are next to each other. The Python script uses the output table from Polygon Neighbors to relate all adjoining polygons and adds a unique ID called Final_ID. Once the script was run, the polygons were dissolved based on Final_ID. The Final_ID links the non-aggregated polygons with the aggregated polygons and with the original NWI attribute table.
2016-04-22T00:00:00Ellen D'AmicoPegasus Technical Services c/o U.S. EPAdamico.ellen@epa.gov26 W. Martin Luther King Dr.Cincinnati OH45268(513) 569-7167Ellen D'AmicoEllen D'AmicoEllen D'AmicoSelection and Buffer of NHD:
Three datasets within the NHD were used to create the buffers: NHDFlowline, NHDWaterbody, and NHDArea.
Streams/ rivers (Ftype = 460), canal/ ditches (Ftype = 336) and named artificial paths (Ftype = 558 AND GNIS_Name is not null) were extracted from the NHDFlowline. Canals were included to avoid areas with highly irrigated land (mostly in coastal regions) being miscalculated as isolated. (Note: All rivers in Ftype = 460 were used; we did not differentiate between perennial, intermittent, and ephemeral.)
If a state had a coastline (Ftype = 566) then a coastline layer was also created from the NHDFlowline data layer.
Lakes/ponds and reservoirs (Ftype = 390 or Ftype = 436, respectively) were selected from the NHDWaterbody dataset. Polygons of streams/ rivers (Ftype = 460) were extracted from the NHDArea dataset.
In order to avoid buffering small ponds and lakes in the NHD that could potentially be geographically isolated wetlands, a procedure was designed to define which polygons were to be buffered.
All polygons in the NHDWaterbody dataset that were greater than 20 acres that also overlapped wetlands in the NWI with Wetland_Type = ‘Lakes’ were buffered.
All named (GNIS_Name is not null) polygons in the NHDWaterbody dataset that overlapped any wetlands in the NWI that were less than 20 acres and greater than 3.79 acres were also buffered.
Any polygon in the NHDWaterbody dataset designated as a water treatment facility (FCode > = 43609 and FCode < 44100) were excluded from the buffering.
In addition any polygons in the NHDWaterbody dataset that was designated as Aquaculture (FCode = 43601) and not already removed from consideration were examined against aerial photographs (Bing) to see if they were net pens. Any polygon that was found to be a net pen was not buffered. This step was necessary because often net pens were digitized as groups instead of individually.
The selected NHDArea, NHDWaterbody, NHDFlowline and Coastline (if applicable) were buffered for 10 meters.
2016-04-22T00:00:00Ellen D'AmicoPegasus Technical Services c/o U.S. EPAdamico.ellen@epa.gov26 W. Martin Luther King Dr.Cincinnati OH45268(513) 569-7167Ellen D'AmicoEllen D'AmicoEllen D'AmicoOverlap Analysis
In order to identify non-floodplain wetlands, a buffer overlap analysis was implemented using the aggregated NWI polygons and buffered NHD. A wetland polygon was considered geographically isolated if it did not overlap any of the buffers and was not adjacent to any riverine wetlands. Three new fields were added to the aggregated NWI polygons: AdjRiverine, AdjBuffer, and Isolated.
If both AdjRiverine and AdjBuffer were null then the polygon was considered geographically isolated.
(Note: If a state abutted a Great Lake, then the boundary of the Great Lake was treated as coastline and buffered. The Great Lake boundaries were downloaded from the Natural Earth website - http://www.naturalearthdata.com/.)
2016-04-22T00:00:00Ellen D'AmicoPegasus Technical Services c/o U.S. EPAdamico.ellen@epa.gov26 W. Martin Luther King Dr.Cincinnati OH45268(513) 569-7167Ellen D'AmicoEllen D'AmicoEllen D'AmicoThis data set represents the extent of wetlands and deepwater habitats that can be determined with the use of remotely sensed data and within the timeframe for which the maps were produced. Wetlands are shown in all of the conterminous 48 states and the District of Columbia. The accuracy of image interpretation depends on the quality of the imagery, the experience of the image analysts, the amount and quality of the collateral data, and the amount of ground truth verification work conducted.
There is a margin error inherent in the use of imagery, thus, detailed on-the-ground inspection of any particular site may result in revision of the wetland boundaries or classification established through image analysis.
Wetlands or other mapped features may have changed since the date of the imagery and/or field work. There may be occasional differences in polygon boundaries or classifications between the information depicted on the map and the actual conditions on site.
For additional information: Identification of Putative Geographically Isolated Wetlands of the Conterminous United States, CR Lane, E D'Amico. 2016. JAWRA Journal of the American Water Resources Association 52 (3), 705-722 https://doi.org/10.1111/1752-1688.12421
Informal Quality Review2016-04-22T00:00:00Tests for integrity have not been performed by EPA Office of Research and Development.1This data is a subset of the National Wetland Inventory. Although nested polygons have been aggregated, the horizontal accuracy is consistent with the original NWI dataset.
For additional information: Identification of Putative Geographically Isolated Wetlands of the Conterminous United States, CR Lane, E D'Amico. 2016. JAWRA Journal of the American Water Resources Association 52 (3), 705-722 https://doi.org/10.1111/1752-1688.12421
Informal Quality Review2016-04-22T00:00:00Tests for integrity have not been performed by EPA Office of Research and Development. 139C6C6B6-EECD-40DE-9EA6-5FDE48A95C27