National Wetlands Inventory Data

Citation:

Citation Information:

Originator: U.S. Fish & Wildlife Service, National Wetlands Inventory
Publication Date: 1979-1994
Title: National Wetlands Inventory Data
Geospatial Data Presentation Form: map
Publication Information:

Publication Place: St. Petersburg, Florida
Publisher: U.S. Fish & Wildlife Service, National Wetlands Inventory

Description:

Abstract:
NWI 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 county coverages containing ground planimetric coordinates of wetlands point, line, and area features and wetlands attributes. The digital data as well as the hardcopy maps that were used as the source for the digital data are produced and distributed by the U.S. Fish & Wildlife Service's National Inventory project.
Purpose:
The data provide consultants, planners, and resource managers with information on wetland location and type. The purpose of this survey was not to map all wetlands and deepwater habitats, but rather, to use aerial photointerpretation techniques to produce thematic maps that show, in most cases, the larger types that can be identified by such techniques. The objective was to provide better geospatial information on wetlands than found on the USGS topoquads.
Time Period of Content:

Time Period Information:

Multiple Dates/Times:

Single Date/Time:

Calendar Date: 1971
Time of Day: 00:00:00

Currentness Reference: photography date

Status:

Progress: In Work
Maintenance and Update Frequency: Irregular

Keywords:

Theme:

Theme Keyword Thesaurus: none
Theme Keyword: nwi
Theme Keyword: wetlands
Theme Keyword: hydrologic
Theme Keyword: land cover
Theme Keyword: surface and manmade features

Place:

Place Keyword Thesaurus: none
Place Keyword: Michigan

Stratum:

Stratum Keyword Thesaurus: none

Temporal:

Temporal Keyword Thesaurus: none

Point of Contact:

Contact Information:

Contact Organization Primary:

Contact Organization: MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography
Contact Person: MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography

Contact Address:

Address Type: mailing and physical address
Address: P.O. Box 30448, Stephens T Mason Building
City: Lansing
State or Province: MI
Postal Code: 48909-7984
Country: USA

Contact Voice Telephone: (517) 241-2254
Contact Facsimile Telephone: (517) 335-3264
Hours of Service: 8:00a.m. - 5:00p.m.

Data Set Credit: U.S. Fish & Wildlife Service
Security Information:

Security Classification System: none
Security Classification: Unclassified
Security Handling Description: none

Native Data Set Environment: Windows NT, ARC/INFO version 7.2.1, ArcView 3.0
Cross Reference:

Citation Information:

Originator: Michigan Department of Natural Resources
Publication Date: pre-1990
Title: MIRIS Base
Publication Information:

Publication Place: Lansing, MI
Publisher: MDNR

Cross Reference:

Citation Information:

Originator: Michigan Department of Natural Resources
Publication Date: 1978
Title: Land Cover /Use
Geospatial Data Presentation Form: document
Publication Information:

Publication Place: Lansing, MI
Publisher: Michigan Department of Natural Resources

Cross Reference:

Citation Information:

Originator: Michigan Department of Natural Resources
Publication Date: 1978
Title: Statewide Aerial Photography (acquired June - September)
Geospatial Data Presentation Form: color infrared film
Publication Information:

Publication Place: Lansing, MI
Publisher: Michigan Department of Natural Resources

Larger Work Citation:

Citation Information:

Originator: Michigan Department of Natural Resources
Publication Date: 1999
Title: MDNR, 1978 Land Cover / Use
Geospatial Data Presentation Form: map
Series Information:

Series Name: Land Cover / Use

Cross Reference:

Citation Information:

Title: U.S. Fish & Wildlife Service

Attribute Accuracy:

Attribute Accuracy Report:
Attribute accuracy is tested by manual comparison of the source with hard copy printouts and/or symbolized display of the digital wetlands data on an interactive computer graphic system. In addition, WAMS software (USFWS-NWI) tests the attributes against a master set of valid wetland attributes.
Logical Consistency Report:
Polygons intersecting the neatline are closed along the border. Segments making up the outer and inner boundaries of a polygon tie end-to-end to completely enclose the area. Line segments are a set of sequentially numbered coordinate pairs. No duplicate features exist nor duplicate points in a data string. Intersecting lines are separated into individual line segments at the point of intersection. Point data are represented by two sets of coordinate pairs, each with the same coordinate values. All nodes are represented by a single coordinate pair which indicates the beginning or end of a line segment. The neatline is generated by connecting the four corners of the digital file, as established during initialization of the digital file. All data crossing the neatline are snapped to the neatline. Tests for logical consistency are performed by WAMS verification software (USFWS-NWI).
Completeness Report:
All photointerpretable wetlands are mapped given considerations of map and photo scale and state-of-the-art wetland delineation techniques. The target mapping unit is an estimate of the minimum-sized wetland that should be consistently mapped. It is not the smallest wetland that appears on the map, but instead it is the size class of the smallest group of wetlands that NWI attempts to map consistently. Users must realize however that some wetland types are conspicuous and readily identified (e.g., ponds) and smaller wetlands of these types may be mapped. Other types (drier-end wetlands and forested wetlands, especially evergreen types) are more difficult to photointerpret and larger ones may be missed. In forested regions, the target mapping unit varies with the scale of the aerial photographs given acceptable quality (e.g., captured during spring, leaf-off condition for deciduous trees). This means that where 1:58,000 photography was used, the NWI maps should show most wetlands larger than 1 - 3 acres. In the treeless prairies, 1/4-acre wetlands are typically mapped due to the openness of the terrain and occurrence of wetlands in distinct depressions. In forested regions, small open water and emergent wetlands may also be mapped where conspicuous. Map users must pay close attention to the photo scale used to prepare the maps. Also, users should be aware that black and white imagery tends to yield more conservative interpretations than color infrared imagery, except when the latter was acquired during a dry year, complicating wetland detection. In most areas, farmed wetlands are not mapped, with exceptions including prairie pothole-type wetlands, cranberry bogs, and diked former tidelands. Mucklands and other farmed wetlands are usually not shown on the maps. As mentioned in the "Use_Constraints" section, no attempt was made to separate regulated wetlands from other wetlands, as these decisions must be based on criteria established by Federal and state regulatory agencies. Maps produced by photointerpretation techniques will never be as accurate as a detailed on-the-ground delineation, so the boundaries on the NWI maps should be considered generalized, especially in areas of low topographic relief (e.g., glaciolacustrine plains). Partly drained wetlands may also be conservatively mapped, since they may be difficult to photointerpret and in many cases, require site-specific assessment for validation.
Positional Accuracy:

Horizontal Positional Accuracy:

Horizontal Positional Accuracy Report: Accuracy was tested by manual comparison of the source with hard copy printouts.

Lineage:

Source Information:

Source Citation:

Citation Information:

Originator:
Domain includes US Geological Survey (USGS), US Department of Agriculture (USDA), National Aeronautics and Space Administration (NASA), special project. Information for this element varies for each 7.5' quad.
Publication Date: 2/71-12/92
Title: NAPP, NHAP, ASCS, NASA

Source Time Period of Content:

Time Period Information:

Multiple Dates/Times:

Single Date/Time:

Calendar Date: Unknown

Source Citation Abbreviation: NWI1

Source Information:

Source Citation:

Citation Information:

Originator: US Geological Survey
Publication Date: 1902-1992
Title: Topographic Map
Geospatial Data Presentation Form: map
Publication Information:

Publication Place: Reston, VA
Publisher: US Geological Survey

Source Time Period of Content:

Source Currentness Reference: publication date

Source Citation Abbreviation: NWI2

Source Information:

Source Citation:

Citation Information:

Originator: U.S. Fish & Wildlife Service, National Wetlands Inventory
Publication Date: 1979-1994
Title: National Wetlands Inventory
Geospatial Data Presentation Form: map
Publication Information:

Publication Place: St. Petersburg, FL
Publisher: U.S. Fish & Wildlife Service, National Wetlands Inventory

Source Time Period of Content:

Source Currentness Reference: publication date

Source Citation Abbreviation: NWI3

Process Step:

Process Description:
NWI maps were compiled through manual photointerpretation (using Cartographic Engineering 4X Mirror Stereoscopes) of NHAP or NAPP aerial photography supplemented by Soil Surveys and field checking of wetland photo signatures. Delineated wetland boundaries were manually transferred from interpreted photos to USGS 7.5 minute topographic quadrangle maps and then manually labeled. Quality control steps occurred throughout the photointerpretation, map compilation, and map reproduction processes.
Source Used Citation Abbreviation: NWI1
Source Used Citation Abbreviation: NWI2
Process Date: 1979-1994

Process Step:

Process Description:
Digital wetlands data were either manually digitized or scanned from stable-base copies of the 1:24,000 scale wetlands overlays registered to the standard U.S. Geological Survey (USGS) 7.5 minute quadrangles into topologically correct data files using Wetlands Analytical Mapping System (WAMS) software. Files contain ground planimetric coordinates and wetland attributes. The quadrangles were referenced to the North American Datum of 1927 (NAD27) horizontal datum. The scanning process captured the digital data at a scanning resolution of at least 0.0001 inches; the resulting raster data were vectorized and then attributed on an interactive editing station. Manual digitizing used a digitizing table to capture the digital data at a resolution of at least 0.005 inches; attribution was performed as the data were digitized. The determination of scanning versus manual digitizing production method was based on feature density, source map quality, feature symbology, and availability of production systems. The data were checked for position by comparing plots of the digital data to the source material.
Source Used Citation Abbreviation: NWI3

Process Step:

Process Description: Images were converted from 8 bit gray scale to 1 bit black & white PCX file format.

Process Step:

Process Description: Converted PCX image files were auto-vectorized through a centerline conversion process, using commercially available software. The output of the files were in a DXF file format.

Process Step:

Process Description:
DXF files were imported in MDNR delivered dgn seed files. The MIRIS seed files were setup for State Plane Coordinate System (1927). Vector line work was warped, using commercially available software. Warping variables as follows; a) Registration points. There were four registration points used for warping. These were the four corners of the 7.5' quadrangle maps which occurred in both the imported DXF data, and the MIRIS source data. B) Transformation of the vector line work used an affine method, using a uniform least squares weighting. C) Original vectorized registration points are resident on level 61 or 60 of delivered design files.
Process Step:

Process Description: Source Image Referencing. Source images were also placed and registered in the design files using the same above-mentioned registration points.

Process Step:

Process Description:
Data Input. All data was per MDNR suggested level/symbology scheme. Operators input the following information within Microstation, using the NWI paper maps as a reference guide; a) Wetland type as a text string within auto-vectorized polygons. B) Re-input continuous line work for linear and shared linear/boundary line work, as the auto-vectorized data may not be continuous due to vectorizing process. This was done by the operator 'heads up' digitizing over the warped image data. These features were also isolated by level and color from each other. C) Text labels for linear and shared boundary line work. D) No label identifiers. Wetland polygons encountered having no text identifier were coded with a symbol on level 1. E) Duplicate label identifiers. Wetland polygons encountered having more than one text identifier were coded with all text identifiers on level 55 or 56.
Process Step:

Process Description:
Line Work Cleaning. All line work was run through commercially available software for; duplicate lines; zero length lines and clean intersections. Auto-bending of line work was allowed using a five foot tolerance. This auto-bending facilitated creation of clean intersections within the tolerance box.
Process Step:

Process Description:
Error checking. The following error checking process was used: a) Menu System. A menu system was developed so that any operator placed feature was placed on the correct level with the correct symbology. B) Topology Creation. The creation of topology files ensured that all line work was clean. C) Zero Area Centroids. Queries created to check each design file for any operator placed centroid which had a measured area of zero. This would indicate the presence of two operator placed centroids within the same polygon. D) Topology Comparison. A spatial analysis was conducted on each design file to compare software generated centroids against operator placed centroids. This process illustrated areas where the operator had missed the placement of centroids. E) Visual Check. The final error checking process was to plot each design file, overlay it with the original paper map and visually check both centroids and line work for correctness.
Process Step:

Process Description:
Polygon wetlands in digitized Intergraph NWI 7.5 minute quadrangle files were converted to Arc/Info coverages using IGDSARC. Polygon topology was created using build and clean. Any labelerrors and nodeerrors were located and corrected. Linear wetlands were not converted at this time.
Process Step:

Process Description:
Coverages were imported to ArcView and queried to check for errors in NWI_CODE. Invalid codes, coding errors and missing codes were corrected, where clearly warranted, to allow for a future process of dissolving polygons. Attempts were made to retain as much original data as possible. Polygons which could not be identified with any NWI_CODE were labeled '999' in keeping consistency with digitizing processing and to prevent loss of polygon. As a quality check, many quadrangles were also compared to original Intergraph files by overlaying and checking for complete polygon topology.
Process Step:

Process Description: Quadrangle coverages were reprojected from Stateplane NAD27 to MI Geo Ref NAD83 and adjoining polygons with a similar NWI_CODE dissolved together.

Process Step:

Process Description:
Quadrangle coverages were mapjoined into county coverages and clipped using 1:24,000 MIRIS county base map. Counties adjoining the Great Lakes were clipped by using existing county interior linework and extending over water with 1:100,000 dlg linework, derived from TIGER.
Process Step:

Process Description:
Clipped county coverages were cleaned, unlabeled sliver polygons eliminated (some done manually), and similar adjacent polygons dissolved together. Polygons with AREA < 100 sq. meters were eliminated to reduce sliver and very small polygons.
Process Step:

Process Description:
Several fields were added to tables from existing information in order to enhance usability. The ACRES field was calculated from AREA. The remaining new fields were derived by breaking down the NWI_CODE into component parts, based upon wetland classification hierarchy, with the use of an aml with many selection/reselection criteria.
Cloud Cover: 0

Direct Spatial Reference Method: Vector
Point and Vector Object Information:

SDTS Terms Description:

SDTS Point and Vector Object Type: GT-polygon composed of chains

SDTS Terms Description:

SDTS Point and Vector Object Type: Point

SDTS Terms Description:

SDTS Point and Vector Object Type: String

Horizontal Coordinate System Definition:

Planar:

Grid Coordinate System:

Grid Coordinate System Name: Other Grid System's Definition
Other Grid System's Definition:

Other Grid System's Definition: Michigan GeoRef from Oblique Mercator projection, Scale factor at center line = 0.9996, Azimuthal angle = 337.25556, False easting = 2546731.496, False northing = -4354009.816

Planar Coordinate Information:

Planar Coordinate Encoding Method: Coordinate Pair
Planar Distance Units: meters

Geodetic Model:

Horizontal Datum Name: North American Datum of 1983
Ellipsoid Name: Geodetic Reference System 80
Semi-major Axis: 6378206.4
Denominator of Flattening Ratio: 294.9787

Detailed Description:

Entity Type:

Entity Type Label: wetland
Entity Type Definition:
Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. For purposes of this classification, wetlands must have one or more of the following three attributes: 1) at least periodically, the land supports predominantly hydrophytes; 2) the substrate is predominantly undrained hydric soil; and 3) the substrate is non-soil and is saturated with water or covered by shallow water at some time during the growing season of each year.
Entity Type Definition Source: Cowardin, L.M., V. Carter, F. Golet, and E. LaRoe, 1979, Classification of Wetlands and Deepwater Habitats of the Unites States, U.S. Fish & Wildlife Service, 103 pp.

Attribute:

Attribute Label: wetland classification
Attribute Definition: classification of the wetland
Attribute Domain Values:

Codeset Domain:

Codeset Name: valid wetland classification code list
Codeset Source: Photointerpretation Conventions for the National Wetlands Inventory, March 1990

Detailed Description:

Entity Type:

Entity Type Label: Polygon Attribute Table (PAT)

Attribute:

Attribute Label: ACRES
Attribute Definition: Acres of each individual polygon as computed from the AREA field. Equation is ACRES=Area/4046.87

Attribute:

Attribute Label: AREA
Attribute Definition: Polygon area calculated by Arc/Info.

Attribute:

Attribute Label: CLASS
Attribute Definition:
Class describes the general appearance of the habitat in terms of either the dominant life form of the vegetation or the physiography and composition of the substrate, with the life form assignment having precedence over physiography.
Attribute:

Attribute Label: CODE_ERR
Attribute Definition: Field used to sort any NWI_CODE with uncertain or erroneous wetland types, and which were not corrected.

Attribute:

Attribute Label: County#
Attribute Definition: Sequential polygon order, internally assigned by Arc/Info.

Attribute:

Attribute Label: County-ID
Attribute Definition: Unique numbering sequence for polygons within each cover, assigned by Arc/Info.

Attribute:

Attribute Label: NWI_CODE
Attribute Definition: Unique label for each occurrence of a wetland type within Michigan based upon the original wetland types as coded by the U.S. Fish & Wildlife Service.

Attribute:

Attribute Label: PERIMETER
Attribute Definition: Polygon perimeter, sum of arcs, calculated by Arc/Info.

Attribute:

Attribute Label: SEC_CLASS
Attribute Definition: Secondary class (see class) assigned to wetland, denoting lower level of precedence; primarily used in palustrine wetlands.

Attribute:

Attribute Label: SHAPE
Attribute Definition: Attribute identifier used internally by ArcView.

Attribute:

Attribute Label: SPEC_MOD
Attribute Definition:
Field includes special modifiers, water chemistry, and soil type, with water chemistry and soil used only infrequently for Michigan wetlands. Special modifiers indicate wetlands or deepwater habitats modified or created by man or beaver. Water chemistry is based upon inland salinity, soil is simply either organic or mineral.
Attribute:

Attribute Label: SUBCLASS
Attribute Definition: Subclass is a finer definition of the specific class level.

Attribute:

Attribute Label: SUBSYSTEM
Attribute Definition: Subsystem is a subdivision of the system level into more specific categories.

Attribute:

Attribute Label: SYSTEM
Attribute Definition: System refers to a complex of wetlands and deepwater habitats that share the influence of similar hydrologic, geomorpholic, chemical, or biological factors.

Attribute:

Attribute Label: WATER
Attribute Definition: Water regime modifier for freshwater, non-tidal wetlands.

Detailed Description:

Entity Type:

Entity Type Label: Text Attribute Table (TATIGDS)

Attribute:

Attribute Label: Text
Attribute Definition: Contains original NWI_CODE as digitized; values not modified during process steps; useful for display purposes only, not carried over into shapefiles.

Overview Description:

Entity and Attribute Overview:
The wetland classification system is hierarchical, with wetlands and deepwater habitats divided among five major systems at the broadest level. The three systems found in Michigan include Riverine (rivers, creeks, and streams), Lacustrine (lakes and deep ponds), and Palustrine (shallow ponds, marshes, swamps, sloughs). Systems are further subdivided into subsystems which reflect hydrologic conditions. Below the subsystem is the class which describes the appearance of the wetland in terms of vegetation or substrate. Each class is further subdivided into subclasses; vegetated subclasses are described in terms of life form and substrate subclasses in terms of composition. The classification system also includes modifiers to describe hydrology (water regime), soils, water chemistry (pH, salinity), and special modifiers relating to man's activities (e.g., impounded, partly drained).
Entity and Attribute Detail Citation:
For general NWI information please refer to the NWI Homepage (http://www.nwi.fws.gov). For more details on the NWI coding structure please see the NWI mapcode download site (ftp://www.nwi.fws.gov/maps/mapcode.txt). Please refer to Classification of Wetlands and Deepwater Habitats of the United States (Cowardin, et al. 1979) for a more detailed explanation of NWI classification and heirarchy. (http://www.nwi.fws.gov/classifman/classman9.html).

Distributor:

Contact Information:

Contact Person Primary:

Contact Person: McDonald, Donald
Contact Organization: MDNR Land and Mineral Services Division, Resource Mapping and Aerial Photography Section

Contact Address:

Address Type: mailing address
Address: P.O. Box 30448
City: Lansing
State or Province: MI
Postal Code: 48909-7948
Country: USA

Contact Voice Telephone: 517-373-2534
Contact Facsimile Telephone: 517-335-3264
Contact Electronic Mail Address: mcdonald@state.mi.us
Hours of Service: 7:30 a.m. - 4:30 p.m.

Distribution Liability: MDNR assumes no liability for results or conclusions drawn from use of this data.
Standard Order Process:

Non-digital Form: N/A

Standard Order Process:

Custom Order Process: Inquire about special distribution services.
Technical Prerequisites: Requester is responsible for loading, conversion, use, and interpretation of data.

Metadata Date: 4/21/2000
Metadata Review Date:
Metadata Future Review Date:
Metadata Contact:

Contact Information:

Contact Organization Primary:

Contact Organization: MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography
Contact Person: MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography

Contact Address:

Address Type: mailing and physical address
Address: P.O. Box 30448, Stephens T Mason Building
City: Lansing
State or Province: MI
Postal Code: 48909-7984
Country: USA

Contact Voice Telephone: (517) 241-2254
Contact Facsimile Telephone: (517) 335-3264
Hours of Service: 8:00a.m. - 5:00p.m.

Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Standard Version: 19940608
Metadata Time Convention: local time
Metadata Extensions:

Online Linkage: http://www.nwi.fws.gov
Profile Name: NWI Homepage

Metadata Extensions:

Online Linkage: ftp://www.nwi.fws.gov/maps/mapcode.txt
Profile Name: NWI coding structure

Metadata Extensions:

Online Linkage: http://www.nwi.fws.gov/classifman/classman9.html
Profile Name: Classification of Wetlands and Deepwater Habitats of the United States (Cowardin, et al. 1979)