This data set represents the extent, approximate _location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979), which represents a biological definition of wetlands and deepwater habitats. There is no attempt to define the limits of proprietary jurisdiction of any Federal, State, or local government, or to establish the geographical scope of the regulatory programs of government agencies. Some wetland habitats may be under represented or excluded in certain areas because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters and also some deepwater reef communities (coral or tuberficid worm reefs). These habitats, because of their depth and water clarity, go undetected by most aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project boundaries, specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.

Download In State Plane Projection Here The Lake County Wetland Inventory (LCWI) maps natural and artificial wetlands meeting definitions established by the federal agencies who work with the Lake County Geographic Information System staff to periodically review and update it. These agencies include the United States Environmental Protection Agency, the U.S. Fish and Wildlife Service, the USDA Natural Resources Conservation Service and the United States Army Corps of Engineers. The 1989 federal wetland delineation standards for offsite wetland mapping are used. This data was last published in March of 1993. This update includes changes to the previous version of LCWI including: adjust current wetland boundaries to omit development, including roads; to fine tune boundary placement where that was intended by the original delineation, in some cases, adjust the wetland to photographic features / signature; delete wetlands which the committee decided were mapped in error - for example, trees which were mistaken for wet areas; create polygons for newly delineated artificial wetlands; and newly delineated wetlands or farmed wetlands caused by the continued deterioration of the agricultural drain tile system and increased runoff due to urbanization. The LCWI is a useful tool for general planning and review purposes, but it does not take the place of an on-site delineation by a certified wetland specialist. High resolution (1" = 100') orthorectified aerial imagery captured in April 2002 was used as the base for this update. Other data used as reference for this update include: 2004 SOIL SURVEY GEOGRAPHIC (SSURGO) DATABASE FOR LAKE COUNTY, IL - U.S. Department of Agriculture, Natural Resources Conservation Service; HYDROLOGY2002 - Lake County GIS/Map Division; 2' topography (CONTOURS) - Lake County GIS/Map Division; and various years of historical aerial photography for clarification. By using the more recent higher resolution photography, the resulting updated wetland boundaries are more accurate then the original boundaries published in 1993.

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries. Please reference the metadata for contact information.

In 2016 NYC Parks contracted with the UVM Spatial Analysis Lab to use modern remote sensing and object-based image analysis to create a new wetlands map for New York City. Data inputs include Light Detection and Ranging Data, State and Federal Wetland Inventories, soils, and field data. Because the map was conservative in its wetlands predictions, NYC Parks staff improved the map through a series of desktop and field verification efforts. From June to November 2020, NYC Parks staff field verified the majority of wetlands on NYC Parks' property. The map will be opportunistically updated depending on available field information and delineations. Another dedicated field verification effort has not been planned. As of June 2021, no subsequent updates to the data are scheduled. Original field names were updated to field names that are easier to understand. This dataset was developed to increase awareness regarding the location and extent of wetlands to promote restoration and conservation in New York City. This map does not supersede U.S. Fish and Wildlife Service National Wetlands Inventory (NWI) and New York State Department of Environmental Conservation (NYSDEC) wetlands maps and has no jurisdictional authority. It should be used alongside NWI and NYSDEC datasets as a resource for identifying likely locations of wetlands in New York City. Mapped features vary in the confidence of their verification status, ranging from "Unverified" (meaning the feature exists in its original remotely mapped form and has not been ground truthed) to "Verified - Wetland Delineation" (meaning the boundaries and type of wetland have been verified during an official wetland delineation). Because of the rapid nature of the protocol and the scale of data collection, this product is not a subsitute for on-site investigations and field delineations. The dataset also includes broad classifications for each wetland type, e.g. estuarine, emergent wetland, forested wetland, shrub/scrub wetland, or water. Cowardin classifcations were not used given rapid verfication methods. The accuracy of the wetlands map has improved over time as a result of the verification process. Fields were added over time as necessitated by the workflow and values were updated with information, either from the field verifications, delineation reports, or desktop analysis. OBJECTID, Shape, Class_Name_Final, Verification_Status, Create_Date, Last_Edited_Date, Verification_Status_Year, SHAPE_Length, SHAPE_Area https://www.nycgovparks.org/greening/natural-resources-group Data Dictionary: https://docs.google.com/spreadsheets/d/1a45qCho45MV-AuOlGxyaRp0cg3cRFKw4lAYBIaU3zi4/edit#gid=260500519 Map: https://data.cityofnewyork.us/dataset/NYC-Wetlands/7piy-bhr9

This data layer is an element of the Oregon GIS Framework. The Oregon Wetlands Database (2019) is a geodatabase consisting of three feature classes: 1) Local Wetland Inventory (LWI) Wetlands, 2) National Wetland Inventory (NWI) Wetlands, and 3) More Oregon Wetlands (MOW). Each feature class contains polygons representing wetland boundaries. The three feature classes originated from different sources with distinct purposes, methodologies and time frames for generating geospatial wetlands data, and there is overlap among them; however, all are relevant to the conservation and management of wetlands across the state of Oregon. See the metadata of the individual feature classes for more background information and details per dataset.

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.

This product provides regional estimates of specific wetland types (bog and fen) in Alaska. Available wetland types mapped by the National Wetlands Inventory (NWI) program were re-classed into bog, fen, and other. NWI mapping of wetlands was only done for a portion of the area so a decision tree mapping algorithm was then developed to estimate bog, fen, and other across the state of Alaska using remote sensing and GIS spatial data sets as inputs. This data was used and presented in two chapters on the USGS Alaska LandCarbon Report

This is a map service of the 1972 Wetland Maps. These are guidance maps for regulatory purposes and not (and never were) a wetland delineation.This is a MD iMAP hosted service. Find more information on https://imap.maryland.gov.Image Service Layer Link: https://mdgeodata.md.gov/imap/rest/services/Hydrology/MD_WetlandMaps1972/ImageServer

Note that due to the quantity and complexity of the data there is scale dependent rendering enabled. The vector data only draws when zoomed in to 1:250,000 map scale or larger. To view the wetlands data at a smaller scale utilize the Wetlands Raster service (https://www.fws.gov/wetlandsmapservice/rest/services/Wetlands_Raster/ImageServer) to display generalized wetlands at all scales.. For specific questions or assistance please email wetlands_team@fws.gov.For more information visit: https://www.fws.gov/wetlands/index.htmlView Wetlands Data on the Wetlands Mapper at: https://www.fws.gov/wetlands/Data/Mapper.htmlWetlands Web Services are available at: https://www.fws.gov/wetlands/Data/Web-Map-Services.htmlWetlands Data available as a KML at: https://www.fws.gov/wetlands/Data/Google-Earth.htmlWetlands Data Downloads available at: https://www.fws.gov/wetlands/Data/Data-Download.htmlWetland Data Standards available at: https://www.fws.gov/wetlands/Data/Data-Standards.htmlWetland Codes available at: https://www.fws.gov/wetlands/Data/Wetland-Codes.htm

The State of Connecticut defines inland wetlands based on soils. The Connecticut Inland Wetlands and Watercourses Act defines wetland soils to include any of the soil types designated as poorly drained, very poorly drained, alluvial, or floodplain by the National Cooperative Soil Survey, as may be periodically amended, of the Natural Resources Conservation Service of the United States Department of Agriculture.Map units dominated by Connecticut inland wetland soils may have inclusions of non-wetland soils, and non-wetland map units may have inclusions of Connecticut inland wetland soils. On site investigation is necessary to determine the presence or absence of wetland soils in a particular area.This data set is a digital soil survey and generally is the mostdetailed level of soil geographic data developed by the NationalCooperative Soil Survey. The information was prepared by digitizingmaps, by compiling information onto a planimetric correct baseand digitizing, or by revising digitized maps using remotelysensed and other information.This data set consists of georeferenced digital map data andcomputerized attribute data. The map data are in a soil survey areaextent format and include a detailed, field verified inventoryof soils and miscellaneous areas that normally occur in a repeatablepattern on the landscape and that can be cartographically shown atthe scale mapped. The soil map units are linked to attributes in theNational Soil Information System relational database, which givesthe proportionate extent of the component soils and their properties.

The Lake County Wetland Inventory (LCWI) maps natural and artificial wetlands meeting definitions established by the federal agencies who work with the Lake County Geographic Information System staff to periodically review and update it. These agencies include the United States Environmental Protection Agency, the U.S. Fish and Wildlife Service, the USDA Natural Resources Conservation Service and the United States Army Corps of Engineers.

The 1989 federal wetland delineation standards for offsite wetland mapping are used. This data was last published in March of 1993. This update includes changes to the previous version of LCWI including: adjust current wetland boundaries to omit development, including roads; to fine tune boundary placement where that was intended by the original delineation, in some cases, adjust the wetland to photographic features / signature; delete wetlands which the committee decided were mapped in error - for example, trees which were mistaken for wet areas; create polygons for newly delineated artificial wetlands; and newly delineated wetlands or farmed wetlands caused by the continued deterioration of the agricultural drain tile system and increased runoff due to urbanization.

The LCWI is a useful tool for general planning and review purposes, but it does not take the place of an on-site delineation by a certified wetland specialist.

© Lake County, Illinois GIS/Mapping Division

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.

The National Wetlands Inventory (NWI) dataset was downloaded from the US Fish and Wildlife Service website at https://www.fws.gov/wetlands/Data/State-Downloads.html on 05/04/2021. Metadata derives from original NWI database and updated to reflect the date of download. According to website, this layer was updated last October 1st, 2020. This is a clip of all wetlands features within the Westchester County boundary minus all riverines, Long Island Sound, and the Hudson River.This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.

These data layers show the location and boundaries of regulated wetlands within the City of Boulder boundaries based upon field visits to each site. The mapping typically reflects conditions during the specific year and season when the field work was conducted. This data is the official current regulatory area dataset. Created 2017. Combined all previous wetland datasets into one. Query by Status an Category attributes. Status: Regulatory (currently regulated by the city), Non-Regulatory (outside city limits or not regulated by the City), Revised (not regulated - awaiting City Council acceptance), Proposed (wetland application submitted and pending acceptance) Category: Category A - High functioning wetland with 25-foot inner buffer and 25-foot outer buffer (50-feet total). Category B - Low functioning wetland with 25-foot total buffer. Wetland descriptions and evaluations are available on the City of Boulder Wetland Regulation webpage.

Connecticut Historic Shoreline Wetlands: 1880s NOS T-Sheet Shoreline Features is a 1:10,000-scale, line feature-based layer that includes information depicting historic shoreline features and wetland boundaries for areas of coastal Connecticut during the 1880s. The layer depicts information found on topographic survey sheets (T-sheets) from the US Coast and Geodetic Survey (USC&GS), a predecessor to the National Ocean Service (NOS). The layer represents conditions at a particular point in time. The layer does not depict current conditions. The layer includes ground condition features such as approximate shoreline, shoreline, wetland shoreline, wetland upland boundaries, wetland interior boundaries, man-made shoreline, jetties/breakwaters/groins, and piers/ramps/docks. Semi-submerged marshes, referred to here as "low marshes," ocurring where it is possible to discern marsh-like features waterward of the shoreline are also included. Off shore and riverine islands and rocks may be included depending on the quality of their depiction on the t-sheet. It does not include any non shoreline-centric elements that may have been depicted on the t-sheets such as buildings, roads, bridges, etc., nor does it include other off-shore features like sandbars, mud flats, tidal flats, etc. Features are line locations that represent the approximate location of shoreline features and wetland boundaries. Shoreline, as depicted on the T-sheets that pre-date 1927, reference an approximation of Mean High Water (MHW). Although MHW is technically determined by averaging the height of the high water line, (HWL) the landward extent of the last high tide over a 19 year lunar cycle, USC&GS topographers appoximated MHW by familarizing themselves with the tidal conditions in a given area and noting the assorted physical characteristics of the beach. (For a more complete description of this and other shoreline indicators, the reader is directed to the following article: "Historical Shoreline Change: Error Analysis and Mapping Accuracy," Crowell, M., Leatherman, S., and Buckley, M. Journal of Coastal Research, Vol 7, No. 3, 1991, pp 839-852.) Attribute information is comprised of codes to identify individual features, encode shoreline feature type information, and cartographically represent (symbolize) shoreline features on a map. These codes were derived in part from the National Oceanic & Atmospheric Administration (NOAA) Coastal Services Center (CSC) Historic Digital Shoreline Capture project and modified by the State of Connecticut Department of Environmental Protection to address the inclusion of wetland areas. This data was compiled at 1:10,000 scale. This data is not updated. Purpose: 1880s NOS T-Sheet Shoreline Features is 1:10,000-scale data. It depicts the location of historic shoreline features and wetland boundaries for all of coastal Connecticut with the exception of the area of New Haven Harbor from the West River in West Haven to the New Haven/East Haven town boundary. The features also extend slightly beyond the Connecticut state lines into Rye, New York and Westerly, Rhode Island. Use this layer to display historic shoreline and wetlands. Since this data may be considered a crucial element in land use planning, determination of boundary extents, performing change studies for erosion and accretion examinations and other types of decision making this layer may also be used for analytic purposes. Use this layer with other 1:10,000-scale map data such as any other NOS T-sheet Shoreline or Wetland layers. Not intended for maps printed at map scales greater or more detailed than 1:10,000 scale (1 inch = 833.33 feet.) 1880s NOS T-Sheet Wetland Polygon Features is a 1:10,000-scale, polygon feature-based layer that includes information depicting historic wetlands for areas of coastal Connecticut during the 1880s. The layer depicts information found on topographic survey sheets (T-sheets) from the US Coast and Geodetic Survey (USC&GS), a predecessor to

Exact wetland boundaries are perhaps impossible to delineate. The definition of a wetland can change, and is somewhat open to interpretation. This file represents an attempt to map every polygon that could be considered a wetland using the criteria outlined in the 2007 supplement to the 1987 Army Corps Delineation Manual (Environmental Laboratory. (1987). "Corps of Engineers Wetland Delineation Manual", Technical Report Y-87-1, US Army Engineer Waterways Experiment Station. Vicksburg, MS). To generate the data, stereo paired aerial photos and relatively quick field visits, along with National Wetland Inventory maps and soils data were used. Wetlands that may be non-jurisdictional are also included, such as Depressions, inclusions along rivers and in braided river valleys. Environment

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.Download Link: https://www.fws.gov/wetlands/data/Data-Download.html

Many maps of open water and wetland have been developed based on three main methods: (i) compiling national/regional wetland surveys; (ii) identifying inundated areas by satellite imagery; (iii) delineating wetlands as shallow water table areas based on groundwater modelling. The resulting global wetland extents, however, vary from 3 to 21% of the land surface area, because of inconsistencies in wetland definitions and limitations in observation or modelling systems. To reconcile these differences, we propose composite wetland (CW) maps combining two classes of wetlands: (1) regularly flooded wetlands (RFW) which are obtained by overlapping selected open-water and inundation datasets; (2) groundwater-driven wetlands (GDW) derived from groundwater modelling (either direct or simplified using several variants of the topographic index). Wetlands are thus statically defined as areas with persistent near saturated soil because of regular flooding or shallow groundwater. To explore the uncertainty of the proposed data fusion, seven CW maps were generated at the 15 arc-sec resolution (ca 500 m at the Equator) using geographic information system (GIS) tools, by combining one RFW and different GDW maps. They correspond to contemporary potential wetlands, i.e. the expected wetlands assuming no human influence under the present climate. To validate the approach, these CW maps were compared to existing wetland datasets at the global and regional scales: the spatial patterns are decently captured, but the wetland extents are difficult to assess against the dispersion of the validation datasets. Compared to the only regional dataset encompassing both GDWs and RFWs, over France, the CW maps perform well and better than all other considered global wetland datasets. Two CW maps, showing the best overall match with the available evaluation datasets, are eventually selected. They give a global wetland extent of 27.5 and 29 million km², i.e. 21.1 and 21.6% of global land area, which is among the highest values in the literature, in line with recent estimates also recognizing the contribution of GDWs. This wetland class covers 15% of global land area, against 9.7% for RFWs (with an overlap ca 3.4 %), including wetlands under canopy/cloud cover leading to high wetland densities in the tropics, and small scattered wetlands, which cover less than 5% of land but are very important for hydrological and ecological functioning in temperate to arid areas. […]

Digital wetlands data are intended for use with base maps and digital aerial photography at a scale of 1:12,000 or smaller. Due to the scale, the primary intended use is for regional and watershed data display and analysis, rather than specific project data analysis. The map products were neither designed nor intended to represent legal or regulatory products. Questions or comments regarding the interpretation or classification of wetlands or deepwater habitats can be addressed by visiting https://www.fws.gov/faqs

Due to the quantity and complexity of the wetlands data the wetlands only display at 1:250,000 scale and greater. For wetland information visit https://www.fws.gov/program/national-wetlands-inventory