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TwitterThis 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.
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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.
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TwitterThis data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Trust Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). Certain wetland habitats may be excluded 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.The U.S. Fish and Wildlife Service (Service) is the principal Federal agency that provides information to the public on the extent and status of the Nation's wetlands. The Service's strategic plan for our vast national wetland data holdings is focused on the development, updating, and dissemination of wetlands data and information to Service resource managers and the public.For more information visit: National Wetlands Inventory | U.S. Fish & Wildlife ServiceView Wetlands Data on the Wetlands Mapper at: Wetlands Mapper | U.S. Fish & Wildlife ServiceWetlands Web Services are available at: Wetland Web Mapping Services | U.S. Fish & Wildlife ServiceWetlands Data available as a KML at: View Wetlands Data with a KML file | U.S. Fish & Wildlife ServiceWetlands Data Downloads available at: Download Seamless Wetlands Data | U.S. Fish & Wildlife ServiceWetland Data Standards available at: Federal Data Standards for Wetlands | U.S. Fish & Wildlife Service
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TwitterThis 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
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TwitterThis data layer contains 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.Map Service Link: https://mdgeodata.md.gov/imap/rest/services/Hydrology/MD_WetlandMaps1972/MapServer
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TwitterThe MassDEP Wetlands dataset comprises two ArcGIS geodatabase feature classes:The WETLANDSDEP_POLY layer contains polygon features delineating mapped wetland resource areas and attribute codes indicating wetland type.The WETLANDSDEP_ARC layer was generated from the polygon features and contains arc attribute coding based on the adjacent polygons as well as arcs defined as hydrologic connections.Together these statewide layers enhance and replace the original MassDEP wetlands layers, formerly known as DEP Wetlands (1:12,000). It should be noted that these layers provide a medium-scale representation of the wetland areas of the state and are for planning purposes only. Wetlands boundary determination for other purposes, such as the Wetlands Protection Act MA Act M.G.L. c. 131 or local bylaws must use the relevant procedures and criteria.The original MassDEP wetlands mapping project was based on the photo-interpretation of 1:12,000, stereo color-infrared (CIR) photography, captured between 1990 and 2000, and included field verification by the MassDEP Wetlands Conservancy Program (WCP). In 2007 the MassDEP WCP began a statewide effort to assess and where necessary update the original wetlands data. The MassDEP WCP used ESRI ArcGIS Desktop software, assisted by the PurVIEW Stereo Viewing extension, to evaluate and update the original wetlands features based on photo-interpretation of 0.5m, (1:5,000) digital stereo CIR imagery statewide, captured in April 2005. No field verification was conducted on this updated 2005 wetlands data.The 2005 WETLANDSDEP_POLY layer includes polygon features that distinguish it from its predecessor by overall changes in size and shape. In addition, new polygons have been created and original ones deleted. Many of the polygons, however, remain the same as in the original layer. All changes have been made according to the techniques described below. For the purpose of cartographic continuity, a small number of coastal polygons outside the state boundary where added based on data provided by the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA).The 2005 WETLANDSDEP_ARC layer was generated to support map display and was designed to cartographically enhance the rendering of wetland features on a base map. Arc features in this layer were generated from the wetland polygons and coding (ARC_CODE) was assigned based on the adjacent polygon types. Hydrologic connection features (ARC_CODE = 7) were then added. Where delineated, these arc features indicate an observed hydrologic connection to or between wetland polygons. Although efforts were made to be comprehensive and thorough in mapping hydrologic connections, due to the limitations of aerial photo-interpretation some areas may have been missed.The types of updates made to the original wetland features include alteration, movement/realignment and reclassification. In some cases original wetland areas have been deleted and new areas have been added. Updates to original wetland features resulted from the following factors: changes in the natural environment due to human activity or natural causes; advances in the field of remote sensing, allowing for more refined mapping.Edit changes to the original wetland data include:Addition of new wetland and hydrologic connection featuresAppending (expansion or realignment) of existing (original) wetland and hydrologic connection featuresReclassification of wetlands features, due to change in wetlands environment from the original classificationMovement (or shifting) of original wetland features to better match the source imageryDeletion of original wetland or hydrologic connection features due to changes in wetlands environment or inconsistency with mapping criteria.Please note that although efforts were made to be comprehensive and thorough in the evaluation and mapping of statewide wetland resources some areas of the state may have been missed. Many of the wetland and hydrologic connection features remain the same as in the original data. The polygon attribute SOURCE_SCALE may be used to identify areas that have been altered from the original wetlands. The SOURCE_SCALE code 5000 indicates an updated wetland area. The SOURCE_SCALE code 12000 indicates an unaltered, original wetland polygon.
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TwitterThe principal focus of the wetland inventory is to produce wetland maps that are graphic representations of the type, size and location of wetlands in Wisconsin. Currently, there are two different datasets that have been created using different mapping methods and technologies.
The majority of the state was mapped using traditional stereo-pair, black-and-white, infrared photography. Within this context, the objective was to provide reconnaissance level information on the location, type, size of these habitats such that they are accurate at the nominal scale of the 1:20,000 (1 inch = 1667 feet) base map.
LiDAR Technology
LiDAR has advanced the ability to see and map wetland and surface water features.
New wetland mapping is underway in areas across the state at a nominal scale of 1:2000 (1 inch = 166.7 feet). The data are being mapped according to the National Wetland Inventory standards using new methods. Please see the WWI SOP for more information.
See LiDAR based status map for more information.
Data
The download contains both the older, high altitude, stereo-photo based mapping as well as the newer LiDAR based mapping. Any older WWI data within a new project area boundary have been removed.
The DNR recognizes the limitations of using remotely sensed information as the primary data source. They are to be used as a guide for planning purposes.
There is no attempt, in either the design or products of this inventory, to define the limits of jurisdiction of any federal, state, or local government or to establish the geographical scope of the regulatory programs of government agencies. Anyone intending to engage in activities involving modifications within or adjacent to wetland areas should seek the advice of appropriate federal, state, or local agencies concerning specified agency regulatory programs and jurisdictions that may affect such activities. The most accurate method of determining the legal extent of a wetland for federal or state regulations is a field delineation of the wetland boundary by a professional trained in wetland delineation techniques.
See https://dnr.wi.gov/topic/wetlands/inventory.html for more information on Wisconsin Wetland Inventory mapping.
Please contact Calvin Lawrence, GIS Specialist in the WDNR Waterway and Wetlands Section, at Calvin.Lawrence@wisconsin.gov.
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Contact Jes Skillman if you want to add an item to this gallery.Wetland Mapping Group: https://duinc.maps.arcgis.com/home/group.html?id=c22ee7bff919440ba4fac4503723779f#overview
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TwitterThis 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.
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TwitterNWI digital data files are records of wetlands location and classification as defined by the U.S. Fish & Wildlife Service. This dataset is one of a series available in 7.5 minute by 7.5 minute blocks containing ground planimetric coordinates of wetlands point, line, and area features and wetlands attributes. When completed, the series will provide coverage for all of the contiguous United States, Hawaii, Alaska, and U.S. protectorates in the Pacific and Caribbean. The digital data as well as the hard copy maps that were used as the source for the digital data are produced and distributed by the U.S. Fish & Wildlife Service's National Wetlands Inventory project. The data provide consultants, planners, and resource managers with information on wetland location and type. The data were collected to meet U.S. Fish & Wildlife Service's mandate to map the wetland and deep-water habitats of the United States.The full Kansas geospatial catalog is administered by the Kansas Data Access & Support Center (DASC) and can be found at the following URL: https://hub.kansasgis.org/
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TwitterIn 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 wetland predictions, NYC Parks staff improved the map through a series of desktop and field verification efforts beginning in 2020.The map will be opportunistically updated depending on available information.
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 substitute 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 classifications were not used given rapid verification methods.
The accuracy of the wetlands map has improved over time as a result of the verification process. Fields were modified over time as necessitated by the workflow and values were updated with information, either from the field verifications, delineation reports, construction designs, or desktop reviews.
Https://www.nycgovparks.org/greening/natural-resources-group
Data Dictionary: Https://docs.google.com/spreadsheets/d/1UyJssBTcWSOzfOpP2r45ok_s3wZlc6RQ/edit?usp=sharing&ouid=100172030647057411202&rtpof=true&sd=true
Map: https://data.cityofnewyork.us/dataset/NYC-Wetlands/7piy-bhr9
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TwitterIndiana Wetlands from the USFWS NWI as of October 6, 2022 at https://www.fws.gov/node/264847
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TwitterThis web mapping service is intended to provide information on Iowa's wetlands. In particular, data recorded in the National Wetland Inventory.
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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
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TwitterThis 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
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The European Wetland Map (EWM) improves the current state of knowledge on wetlands across Europe by locating, assessing and merging the latest geospatial data, e.g., on the distribution and types of floodplains and wetlands – coastal, mineral and peatlands in a bottom-up approach. It brings together existing data into a comprehensive, easily accessible resource to make wide spread European wetlands visible and enhance their analysis, understanding and management. The approach is described in the attached report.
The EWM is made up of individual datasets for each of the countries included. A polygon and a raster dataset on the geographical distribution of the wetlands considered is available on country basis in an ArcGIS geodatabase and as a country-specific Geo-TIFF collection (grid size: 1 arcsecond).
This work is part of the research and innovation projects “ALFAwetlands- Wetland restoration for the future” Grant Agreement No. 101056844 and “WET HORIZONS” Grant Agreement No. 101056848, funded by the Horizon Europe Framework Program of the European Union. Moreover, this work is part of the project "Building the European Peatland Initiative: a strong alliance for peatland climate protection in Europe", Grant Agreement No. 81290291. This project is part of the European Climate Initiative (EUKI) of the German Federal Ministry for Economic Affairs and Climate Action (BMWK).
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TwitterWetlands are areas where water is present at or near the surface of the soil during at least part of the year. Wetlands provide habitat for many species of plants and animals that are adapted to living in wet habitats. Wetlands form characteristic soils, absorb pollutants and excess nutrients from aquatic systems, help buffer the effects of high flows, and recharge groundwater. Data on the distribution and type of wetland play an important role in land use planning and several federal and state laws require that wetlands be considered during the planning process. The National Wetlands Inventory (NWI) was designed to assist land managers in wetland conservation efforts. The NWI is managed by the US Fish and Wildlife Service. Dataset SummaryPhenomenon Mapped: WetlandsGeographic Extent: 50 United States plus Puerto Rico, the US Virgin Islands, Palmyra Atoll, Guam, American Samoa, and the Northern Mariana IslandsProjection: Web Mercator Auxiliary SphereVisible Scale: This layer preforms well between scales of 1:1,000,000 to 1:1,000. An imagery layer created from this dataset is also available which you can also use to quickly draw wetlands at smaller scales.Source: U.S. Fish and Wildlife ServiceUpdate Frequency: AnnualPublication Date: October, 2025 This layer was created from the October, 2025 version of the NWI. The features were converted from multi-part to a single part using the Multipart To Singlepart tool. Features with more than 50,000 vertices were split with the Dice tool. The Repair Geometry tool was run on the features, using the OGC option. The layer is published with a related table that contains text fields created by Esri for use in the layer's pop-up. Fields in the table are:Popup Header - this field contains a text string that is used to create the header in the default pop-up System Text - this field contains a text string that is used to create the system description text in the default pop-upClass Text - this field contains a text string that is used to create the class description text in the default pop-upModifier Text - this field contains a text string that is used to create the modifier description text in the default pop-upSpecies Text - this field contains a text string that is used to create the species description text in the default pop-up Codes, names, and text fields were derived from the publication Classification of Wetlands and Deepwater Habitats of the United States. What can you do with this layer?Feature layers work throughout the ArcGIS system. Generally your work flow with feature layers will begin in ArcGIS Online or ArcGIS Pro. Below are just a few of the things you can do with a feature service in Online and Pro.ArcGIS Online Add this layer to a map in the map viewer. The layer is limited to scales of approximately 1:1,000,000 or larger but an imagery layer created from the same data can be used at smaller scales to produce a webmap that displays across the full scale range. The layer or a map containing it can be used in an application.Change the layer’s transparency and set its visibility rangeOpen the layer’s attribute table and make selections and apply filters. Selections made in the map or table are reflected in the other. Center on selection allows you to zoom to features selected in the map or table and show selected records allows you to view the selected records in the table.Change the layer’s style and filter the data. For example, you could set a filter for System Name = 'Palustrine' to create a map of palustrine wetlands only. Add labels and set their propertiesCustomize the pop-up ArcGIS Pro Add this layer to a 2d or 3d mapUse as an input to geoprocessing. For example, copy features allows you to select then export portions of the data to a new feature class.Change the symbology and the attribute field used to symbolize the dataOpen table and make interactive selections with the mapModify the pop-upsApply Definition Queries to create sub-sets of the layerThis layer is part of the Living Atlas of the World that provides an easy way to explore the landscape layers and many other beautiful and authoritative maps on hundreds of topics.Questions?Please leave a comment below if you have a question about this layer, and we will get back to you as soon as possible.
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TwitterThis 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). 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.
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TwitterResources to assist Regional Councils with mapping wetlands to 0.05 hectares as required by the National Policy Statement for Freshwater Management. Please cite the individual resources if you are using them; this is just an online collection for those resources. The resources are three reports (Bartlam and Burge 2024; Burge and Bartlam 2024; Martin et al 2024), and data to accompany Martin et al 2024. Citations are as follows: Bartlam S, Burge OR. 2024. Wetland delineation using desktop methods: a guide. Guidance for regional councils to meet mapping requirements under the NPS-FM 2020. Manaaki Whenua - Landcare Research Contract Report LC4427. Lincoln, New Zealand: Manaaki Whenua - Landcare Research. Burge OR, Bartlam S. 2024. Field guide to wetland types. Guidance for regional councils to meet mapping requirements under the NPS-FM 2020. Manaaki Whenua - Landcare Research Contract Report LC4448. Lincoln, New Zealand: Manaaki Whenua - Landcare Research. Martin B, Schindler J, McMillan A, Burge OR. 2024. Mapping difficult wetlands. Manaaki Whenua - Landcare Research Contract Report LC4468. Lincoln, New Zealand: Manaaki Whenua - Landcare Research.
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TwitterThis 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.