Pennsylvania Spatial Data Access

Abstract:

This data set represents the extent, status, and location of National Wetland Inventory wetland mapping projects for NWI Version 2, Surface Waters and Wetlands. Each project polygon contains information on the type and date of imagery used to map the wetlands and a link to a document about specific mapping techniques and habitat information for that project. Some polygons have been updated in 2017 others not for quite some time. The user need to check the date of each wetland polygon for update years.

This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the conterminous United States. 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.

Purpose:

The present goal of the Service is to provide the citizens of the United States and its Trust Territories with current geospatially referenced information on the status, extent, characteristics and functions of wetlands, riparian, deepwater and related aquatic habitats in priority areas to promote the understanding and conservation of these resources.

Supplemental_Information:

The wetland maps were produced as topical overlays using U.S. Geological Survey topographic maps as the base. The hard copy product is a composite map showing topographic and planimetric features from the USGS map base and wetlands and deepwater habitats from the Service's topical overlay. Thus, the data are intended for use in publications, at a scale of 1:24,000 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 or 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 http://www.fws.gov/wetlands/FAQs.html

These data were developed in conjunction with the publication Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC. FWS/OBS-79/31. Alpha-numeric map codes have been developed to correspond to the wetland and deepwater classifications described.

These spatial data are not designed to stand alone. They form topical overlays to the U.S. Geological Survey 1:24,000 or 1:25,000 scale topographic quadrangles. Note that coastline delineations were drawn to follow the extent of wetland or deepwater features as described by this project and may not match the coastline shown in other base maps.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Arc/INFO format, this metadata file may include some Arc/INFO-specific terminology.

Currentness_Reference:

REQUIRED: The basis on which the time period of content information is determined.

Use_Constraints:

None. Acknowledgement of the U.S. Fish and Wildlife Service and (or) the National Wetlands Inventory would be appreciated in products derived from these data

Address:

555 Lester Ave.

Attribute_Accuracy_Report:

The source data was checked using standard review procedures. Attributes were checked by using visual inspection as well as automated verification routines.  Quality of the attribute information varies with age and mapping protocols used when individual maps were prepared

Logical_Consistency_Report:

Polygon and chain-node topology are present. Every polygon has a label.

Completeness_Report:

This 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 or 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.

Source_Contribution:

Spatial information

Process_Description:

Original stable base hard copy maps of wetland and deepwater habitats were created based on USGS state and quadrangle boundaries. These maps were converted to digital files using various software packages (WAMS, ARC and others). The digital files were stored as ESRI Import/Export files corresponding to a single 1:24,000 USGS quadrangle. These digital files were imported and converted to ESRI Coverage format and checked for topological and attribute errors. All coverages were converted from a UTM map projection to an Alber's Equal Area map projection and the horizontal datum was converted from NAD27 to NAD83 were necessary. Polygons attributed as "Uplands" were removed from the dataset and polygons were merged at quadrangle boundaries where the quadrangle line divided polygons with the same attribute. The data was loaded into a seamless SDE geodatabase for the conterminous United States. These steps were conducted using both Arc Macro Language (AML) and ArcMap editing tools. All point data from the original ESRI Coverages were buffered by 11.28 meters (1/10 of an acre) and incorporated into this polygon feature class. Linear features from the original ESRI Coverages were merged at quadrangle boundaries where the quadrangle line divided lines with the same attribute. Linear data is stored in a separate feature class.

Further data improvements included the conversion of all old wetland codes that contained 'OW' to the new code containing 'UB'. All polygons labeled as 'OUT', 'No Data' and 'NP' were removed from the database.

Process_Description:

The file was converted to NAD83 in geographic coordinates, and saved in geodatabase format.

Process_Description:

Dataset copied.

Attribute_Definition:

Internal feature number.

Attribute_Definition_Source:

ESRI

Attribute_Definition:

Alphanumeric code identifying the wetland classification of the polygon.

Attribute_Definition_Source:

http://www.fws.gov/wetlands/Data/wetlandcodes.html

Attribute_Definition:

Hydrogeomorphic code

Attribute_Definition:

Results of a test for data quality

Attribute_Definition:

Feature geometry.

Attribute_Definition_Source:

ESRI

Attribute_Definition:

Area of the polygon in acres.

Attribute_Definition_Source:

Calculated in an Albers Equal Area projection using ESRI's geometry calculator.

Attribute_Definition:

URL to the wetlands code interpreter

Attribute_Definition_Source:

http://wetlandsfws.er.usgs.gov/NWI/webatx/atx.html

Attribute_Definition:

Area of feature in internal units squared.

Attribute_Definition_Source:

ESRI

Address:

555 Lester Ave.

Hard copy maps can be purchased through Cooperator-Run Distribution Centers. Each Center establishes its own pricing structure, product types and order procedures. View Cooperator-Run Distribution Centers.
The wetlands data can also be viewed by accessing The National Map.

Distribution_Liability:

Although these data have been processed successfully on a computer system at the U.S. Fish and Wildlife Service, no warranty expressed or implied is made by the U.S. Fish and Wildlife Service regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Fish and Wildlife Service in the use of these data.

Ordering_Instructions:

To order files on CD-ROM, please see

Address:

115 Land and Water Building

Distribution_Liability:

The USER shall indemnify, save harmless, and, if requested, defend those parties involved with the development 
and distribution of this data, their officers, agents, and employees from and against any suits, claims, or actions for 
injury, death, or property damage arising out of the use of or any defect in the FILES or any accompanying 
documentation. Those parties involved with the development and distribution excluded any and all implied 
warranties, including warranties or merchantability and fitness for a particular purpose and makes no warranty or 
representation, either express or implied, with respect to the FILES or accompanying documentation, including its
 quality, performance, merchantability, or fitness for a particular purpose. The FILES and documentation are 
provided "as is" and the USER assumes the entire risk as to its quality and performance. Those parties involved
 with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or 
consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.

Address:

555 Lester Ave.

National Wetlands Inventory - Pennsylvania