Galveston Bay, Texas Habitat Data from NWRC
Entry ID: usgs_nwrc_texaswetlands

[ Update this Record ]

Summary
Abstract: This data set consists of digital data describing wetland and upland habitats
in the Galveston Bay and surrounding areas of Texas, in 1979. The data set
includes 42 7.5' quadrangles which were digitized at the U.S. Geological
Survey, National Wetlands Research Center using WAMS (Wetland Analytical
Mapping System), from 1:24,000 scale hard copy maps developed by the National
Wetlands Inventory (NWI). Wetlands were classified according on the NWI maps
using the Cowardin, et al., wetland classification scheme to the level of
salinity modifiers. Uplands were classified using a customized classification
scheme which can be cross-referenced to Anderson, et al., and were added by
NWRC. Digital data are available by 7.5' quadrangles. NASA High altitude
1:65,000 color infrared aerial photographs were photo interpreted for wetland
and upland habitat classifications. Habitat layer was overlaid on USGS Quad
base maps to create the NWI maps. The hard copy 1:24,000 NWI maps were
digitized at the National Wetlands Research Center using WAMS (Wetland
Analytical Mapping System).

Related URL
Link: VIEW EXTENDED METADATA


Geographic Coverage
 N: 30.875 S: 29.25  E: -94.375  W: -95.625

Data Set Citation
Dataset Originator/Creator: U.S. Geological Survey, Biological Resources Division, National Wetlands Research Center
Dataset Title: Galveston Bay, Texas Habitat Data from NWRC
Dataset Release Date: 1980's
Dataset Release Place: Lafayette, Louisiana
Dataset Publisher: USGS, BRD, National Wetlands Research Center
Data Presentation Form: Digital vector data


Temporal Coverage
Start Date: 1956-01-01
Stop Date: 1988-12-31


Location Keywords
OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF MEXICO > GALVESTON BAY
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > TEXAS
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > TEXAS > SOUTH TEXAS


Data Resolution
Latitude Resolution: .61
Longitude Resolution: .61


Science Keywords
BIOSPHERE >TERRESTRIAL ECOSYSTEMS >WETLANDS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >WETLANDS    [Definition]
OCEANS >COASTAL PROCESSES >MARSHES    [Definition]
BIOSPHERE >TERRESTRIAL ECOSYSTEMS >WETLANDS >ESTUARINE WETLANDS    [Definition]
BIOSPHERE >TERRESTRIAL ECOSYSTEMS >WETLANDS >MARSHES    [Definition]
BIOSPHERE >TERRESTRIAL ECOSYSTEMS >WETLANDS >SWAMPS    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >WETLANDS
BIOSPHERE >AQUATIC ECOSYSTEMS >WETLANDS >ESTUARINE WETLANDS
BIOSPHERE >AQUATIC ECOSYSTEMS >WETLANDS >MARSHES
BIOSPHERE >AQUATIC ECOSYSTEMS >WETLANDS >SWAMPS


ISO Topic Category
BIOTA
GEOSCIENTIFIC INFORMATION
INLAND WATERS
OCEANS


Quality
The attribute accuracy was tested using several methods during the data
development phases and completion. Data was 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 tests the attributes. Overall, the attribute accuracy is believed high
due to the multiple cerror-checking steps done redundantly during processing.
Process testing was done on the multiple staff error-checking steps and
software error-checking steps to develop estimates of the accuracy and error
rates. The final accuracy assessment used calculated average accuracy and error
rates for the human stages and software verification stages, which were done
redundantly to insure double checking verification of the data coverages
comprising the data set. Exact tolerances vary with coverages, as does the date
of the processing and testing. The final accuracy values expressed are the best
summation which can be developed from the smaller areas which comprise the data
set. Data has been checked and verified against original maps and over years of
use. The accuracy values expressed represent the final calculated accuracy
estimate of the multiple steps of data development from source photography to
completed data. The actual final should be considered as average and perhaps
conservative or over estimating the percent change of error for areas in this
data set.
This logical consistency report includes information about both general and
specific topological tests and data generation dynamics in the fidelity of
data. Data is inherently polygonal. 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 points 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 for each quad is generated
by connecting four corners of a 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.
All photo-interpretable wetlands are identified and mapped using standard
methodologies and equipment for the photo interpretation phases of the data
development. In the upland areas, 1/4 acre wetlands generally are mapped. In
coastal marsh, swamps, and bottomland hardwood areas, small open water and
emergent wetlands are mapped. In general, the minimum mapping unit is from 1 to
3 acres depending of the wetland type and the scale and emulsion of the source
aerial photography. Some small wetlands, densely broken marsh, and those
wetlands obscured by dense forest cover may not be included in this data set.
Processing of the digital data also follows conventions and standard
methodologies for the time period and within limitations of available
workstation equipment at the date of data development. Processing follows
standard operating procedures as used, developed, and shared by the National
Wetlands Inventory of the U.S. Fish and Wildlife Service. Data products were
completed using similar systems and methodologies which are used by NWI and by
USGS.
For reference points accuracy, the accuracy for the digital data are tested by
visual comparison of the source with hard copy maps, and by understanding of
the hardware tolerances and processing values reported by the software used in
data development. Additional checks on comparison were possible when
georeferencing/rectification was done using the USGS maps, which cite National
Mapping Accuracy Standard compliance.


Access Constraints
It is strongly recommended that this data is directly acquired from the
distributor described above or from another USGS Biological Resources
Division server and not indirectly through other sources which may
have changed the data in some way. The distributor makes no claims as
to the data's suitability for other purposes.


Use Constraints
Acknowledgement of the U.S. Geological Survey, National Wetlands Research
Center as a data source would be appreciated in products developed from these
data, and such acknowledgment as is standard for citation and legal practices
for data source is expected by users of this data. Sharing new data
layers developed directly from these data would also be appreciated by NWRC
staff. Users should be aware that comparison with other data sets for the same
area from other time periods may be inaccurate due to inconsistencies resulting
from changes in mapping conventions, data collection, and computer processes
over time. The distributor shall not be liable for improper or incorrect use of
this data, based on the description of appropriate/inappropriate uses
described in this metadata document. These data are not legal documents and are
not to be used as such.


Keywords
basins
bays
bayous
canals
floodplain
wetlands
marshes
swamps
marshlands
habitats
uplands
vegetation types
land cover types
landform types
coast
coastal
delta
coastal habitats
geographic information system data
classified aerial photography
maps
mapping
National Wetlands Inventory
Gulf of Mexico
Texas
Texas Coast
Coastal Texas
South Texas
Galveston Bay
1956
1979
1988


Data Set Progress
IN WORK


Data Center
Spatial Data and Metadata Server, National Wetlands Research Center, Biological Resources Division, USGS, U.S. Department of the Interior    [Information]
Data Center URL: http://sdms.cr.usgs.gov/

Data Center Personnel
Name: HELENA SCHAEFFER
Phone: 337 266-8696
Fax: 337 266-8616
Email: helena_schaefer at usgs.gov
Contact Address:
U.S. Geological Survey, National Wetlands
700 Cajundome Blvd.
City: Lafayette
Province or State: LOUISIANA
Postal Code: 70506
Country: USA


Personnel
LARRY HANDLEY
Role: INVESTIGATOR
Phone: 337-266-8691
Fax: 337-266-8513
Email: larry_handley at usgs.gov
Contact Address:
U.S. Geological Survey, Biological Resources Division,
National Wetlands Research Center
700 Cajundome Blvd
City: Lafayette
Province or State: Louisiana
Postal Code: 70506
Country: USA


TYLER B. STEVENS
Role: DIF AUTHOR
Phone: (301) 614-6898
Fax: 301-614-5268
Email: Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA



Creation and Review Dates
DIF Creation Date: 2003-06-23
Last DIF Revision Date: 2014-04-11
Future DIF Review Date: 2004-06-29

[ Update this Record ]


Link to Web Site