Wetlands Inventory
information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
quad. See the quad-specific metadata file.
Wetlands Inventory
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 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 Wetlands Inventory project.
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 deepwater habitats of the United
States.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
element varies for each 7.5' quad. See the quad-specific metadata
file.
element varies for each 7.5' quad. See the quad-specific metadata
file.
element varies for each 7.5' quad. See the quad-specific metadata
file.
element varies for each 7.5' quad. See the quad-specific metadata
file.
Rico, Virgin Islands. Information for this element varies for each
7.5' quad. See the quad-specific metadata file.
agencies with jurisdiction over wetlands may define and describe
wetlands in a different manner than that used in this inventory.
There is no attempt, in either the design or products of this
inventory, 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. Persons 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 proprietary jurisdictions
that may affect such activities.
National Wetlands Inventory
Mapping System (WAMS) software version 4.06 running under the
SUNOS 4.x operating system to digitize wetlands information.
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.
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 clipped to the
neatline and data within a specified tolerance of the neatline are
snapped to the neatline. Tests for logical consistency are
performed by WAMS verification software (USFWS-NWI).
mapped. In the treeless prairies, 1/4 acre wetlands are mapped.
In forested areas, small open water and emergent wetlands are
mapped. In general, the minimum mapping unit is from 1 to 3 acres
depending on the wetland type and the scale and emulsion of the
source aerial photography. In regions of the country where
evergreen forested wetlands predominate, wetlands smaller than 3
acres may not be mapped. Thus, a detailed on the ground and
historical analysis of a single site may result in a revision of
the wetland boundaries established through photographic
interpretation. In addition, some small wetlands and those
obscured by dense forest cover may not be included in this dataset.
(USGS), U.S. Department of Agriculture (USDA), National Aeronautics
and Space Administration (NASA), special project. Information for
this element varies for each 7.5' quad. See the quad-specific
metadata file.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
Program (NAPP), National High Altitude Photography (NHAP),
Agricultural and Stabilization Conservation Service (ASCS), NASA
or special project photography. Information for this element
varies for each 7.5' quad. See the quad-specific metadata file.
132,000. Information for this element varies for each 7.5' quad.
See the quad-specific metadata file.
white, color infrared, or natural color aerial photograph film
transparency. Information for this element varies for each 7.5'
quad. See the quad-specific metadata file.
1992. Information for this element varies for each 7.5' quad. See
the quad-specific metadata file.
information
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
24000. 25000, 30000, and 62500. Information for this element
varies for each 7.5' quad. See the quad-specific metadata file.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
Wetlands Inventory
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
7.5' quad. See the quad-specific metadata file.
Wetlands Inventory
24000. 25000, 30000, and 62500. Information for this element
varies for each 7.5' quad. See the quad-specific metadata file.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
classification
manual photointerpretation of NHAP or NAPP aerial photography
supplemented by Soil Surveys and field checking of wetland photo
signatures. Delineated wetland boundaries are manually transferred
from interpreted photos to USGS 7.5 minute topographic quadrangle
maps and then manually labelled. Quality control steps occur
throughout the photointerpretation, map compilation, and map
reproduction processes.
for this element varies for each 7.5' quad. See the quad-specific
metadata file.
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
0.001 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.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
Information for this element varies for each 7.5' quad. See the
quad-specific metadata file.
0.9996
from -159.0 to -63.0. Information for this element varies for each
7.5' quad. See the quad-specific metadata file.
pair
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.
Carter, F. Golet, and E. LaRoe. 1979. Classification of wetlands
and deepwater habitats of the United States. U.S. Fish Wildlife
Service. 103 pp.
Carter, F. Golet, and E. LaRoe. 1979. Classification of wetlands
and deepwater habitats of the United States. U.S. Fish Wildlife
Service. 103 pp.
code list
Conventions for the National Wetlands Inventory, March 1990
classification system is hierarchical, with wetlands and deepwater
habitats divided among five major systems at the broadest level.
The five systems include Marine (open ocean and associated
coastline), Estuarine (salt marshes and brackish tidal water),
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).
Carter, F. Golet, and E. LaRoe. 1979. Classification of wetlands
and deepwater habitats of the United States. U.S. Fish Wildlife
Service. 103 pp.
Photointerpretation Conventions for the National Wetlands
Inventory, March 1990
Center
scales, on diazo paper or mylar, composited with or without the
USGS base map.
192.189.43.33 (dlgdata directory) or http://www.nwi.fws.gov/
to the Internet may connect to NWI's server via anonymous ftp and
download available NWI digital wetlands data in DLG3-Optional
format. Indexes for NWI hardcopy maps and digital data are also
available as well as digital wetlands data in a variety of other
formats (MOSS Export, GRASS vector, DXF, and ARC Export) for 14
sample 7.5 minute quadrangles throughout the USA. To access: ftp
to the NWI server, login as anonymous, enter your e-mail address at
the password prompt, change to the dlgdata directory for DLG data,
change to the maps directory for indexes, change to the samples
directory for a sampling of digital data files in formats other
than DLG. Use the ftp 'get' command to transfer readme file for
further instructions. View the NWI home page by pointing your
World Wide Web browser to the http address shown above.
Model 690MP Unix server. SunOS 4.X operating system.
or 10 Gb)
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(150 Mb)
per inch
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(high density)
or 10 Gb)
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(150 Mb)
per inch
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(high density)
or 10 Gb)
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(150 Mb)
per inch
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(high density)
or 10 Gb)
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(150 Mb)
per inch
available with no internal labels; the logical record length is 80
bytes; the block size is a multiple of 80 up to 8000 bytes
(high density)
set may be retrieved via ftp at no charge. For delivery of digital
data on magnetic tape, the prices are: purchased by single 7.5
minute quad unit: $40 per dataset; purchased in groups of 2 to 6:
$20 per dataset; purchased in groups of 7 or more: $90 base fee
plus $7 per dataset. Non-digital Form - $3.50 per diazo paper map;
$5.25 per diazo mylar map.
floppy disk, a maximum order of 10 quads is allowed. Data may be
ordered in latitude/longitude or State Plane Coordinate System
coordinates (Universal Transverse Mercator coordinates are
standard). Latitude/longitude coordinates are not available with
GRASS format. For this service, the user must order data through
USGS-ESIC for delivery on magnetic media. Please specify the
desired coordinate system when ordering. Non-digital form: specify
wetlands overlay or wetlands overlay composited with USGS base map.
directory for an explanation of the wetland codes. Check NWI's
ftp site, software directory for a program that will parse the
wetland codes to fixed length format. Check NWI's ftp site,
software directory for an AML to convert NWI DLG files to ARC/INFO
coverages.
National Wetlands Inventory
linda@wetlands.nwi.fws.gov
Geospatial Metadata