Metadata also available as


U.S. Fish & Wildlife Service, National Wetlands Inventory, Publication Place: St. Petersburg, Florida
Publication_Date: 1979-1994
Title: 4T_wetlands
Geospatial_Data_Presentation_Form: vector digital data
Abstract: National Wetlands Inventory Data for the KBS 4 Townships area.
Purpose: Support of LTER GIS
Calendar_Date: 1971
Currentness_Reference: photography date
Progress: In work
Maintenance_and_Update_Frequency: Irregular
West_Bounding_Coordinate: -85.547101
East_Bounding_Coordinate: -85.293016
North_Bounding_Coordinate: 42.511130
South_Bounding_Coordinate: 42.329146
Theme_Keyword_Thesaurus: none
Theme_Keyword: NWI
Theme_Keyword: wetlands
Theme_Keyword: hydrolic
Theme_Keyword: land cover
Theme_Keyword: surface and manmade features
Access_Constraints: Public domain.
Use_Constraints: None.
MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography
MDNR, Land and Mineral Services Division, Resource Mapping and Aerial Photography
Contact_Voice_Telephone: (517) 241-2254
Contact_Electronic_Mail_Address: sippel@kbs.msu.edu
Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog

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.
Kellogg Biological Station LTER GIS Lab made these edits: The NWI data were clipped to the KBS 4 Township boundary, the areas (meters squared and acres) were recalculated for the clipped area and the data were reprojected to UTM zone 16 from Michigan Georef. The following describes the process steps of the original NWI data: 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).
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.
Accuracy was tested by manual comparison of the source with hard copy printouts.
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.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.Images were converted from 8 bit gray scale to 1 bit black & white PCX file format.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.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. Source Image Referencing. Source images were also placed and registered in the design files using the same above-mentioned registration points.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.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.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.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.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.Quadrangle coverages were reprojected from Stateplane NAD27 to MI Geo Ref NAD83 and adjoining polygons with a similar NWI_CODE dissolved together.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.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.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.
Source_Used_Citation_Abbreviation: C:\DOCUME~1\sippel\LOCALS~1\Temp\xml35.tmp
Process_Date: 1979-1994
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\DOCUME~1\sippel\LOCALS~1\Temp\xml44.tmp
Cloud_Cover: 0

Direct_Spatial_Reference_Method: Vector
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 2054

Grid_Coordinate_System_Name: Universal Transverse Mercator
UTM_Zone_Number: 16
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -87.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Encoding_Method: coordinate pair
Abscissa_Resolution: 0.000032
Ordinate_Resolution: 0.000032
Planar_Distance_Units: meters
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222

Entity_Type_Label: 4T_wetlands
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Sequential unique whole numbers that are automatically generated.
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Unrepresentable_Domain: Coordinates defining the features.
Attribute_Label: NWI_CODE
Attribute_Label: SYSTEM
Attribute_Label: SUBSYSTEM
Attribute_Label: CLASS
Attribute_Label: SUBCLASS
Attribute_Label: CODE_ERR
Attribute_Label: SEC_CLASS
Attribute_Label: SEC_SUBCLA
Attribute_Label: WATER
Attribute_Label: SPEC_MOD
Attribute_Label: area_m2
Attribute_Label: area_acres

Resource_Description: Downloadable Data
Transfer_Size: 32.496

Metadata_Date: 20070213
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Contact_Person: REQUIRED: The person responsible for the metadata information.
REQUIRED: The mailing and/or physical address for the organization or individual.
City: REQUIRED: The city of the address.
State_or_Province: REQUIRED: The state or province of the address.
Postal_Code: REQUIRED: The ZIP or other postal code of the address.
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Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
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Profile_Name: ESRI Metadata Profile
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Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.6 on Tue Feb 13 11:34:05 2007