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Hydrologic Units Maps of the Conterminous United States for the EPA Clean Air Mapping and Analysis Program (C-MAP)
Entry ID: HUC250k


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Summary
Abstract: The Geographic Information Retrieval and Analysis System (GIRAS) was
developed in the mid 70s to put into digital form a number of data layers which
were of interest to the USGS. One of these data layers was the Hydrologic
Units. The map is based on the Hydrologic Unit Maps published by the U.S.
Geological Survey Office of Water Data Coordination, together with the list
descriptions and name of region, subregion, accounting units, and cataloging
unit. The hydrologic units are encoded with an eight- digit number that
indicates the hydrologic region (first two digits), hydrologic subregion
(second two digits), accounting unit (third two digits), and cataloging unit
(fourth two digits).

The data produced by GIRAS was originally collected at a scale of 1: 250K. Some
areas, notably major cities in the west, were recompiled at a scale of 1: 100K.
In order to join the data together and use the data in a geographic information
system (GIS) the data were processed in the ARC/INFO GUS software package.
Within the GIS, the data were edge matched and the neatline boundaries between
maps were removed to create a single data set for the conterminous United
States.

This data set was compiled originally to provide the National Water Quality
Assessment (NAWQA) study units with an intermediate- scale river basin boundary
for extracting other GIS data layers. The data can also be used for
illustration purposes at intermediate or small scales (1:250,000 to 1:2
million).

[Summary provided by EPA]

Related URL
Link: VIEW EXTENDED METADATA


Link: VIEW EXTENDED METADATA
Description: FGDC metadata on &Hydrologic Units Maps&.


Link: VIEW PROJECT HOME PAGE
Description: Homepage of the National Water-Quality Assessment Program (NAWQA).


Link: VIEW RELATED INFORMATION
Description: Background information on Geographical Information Retrieval and
Spatial Browsing.


Geographic Coverage
 N: 48.29 S: 22.87  E: -65.32  W: -127.91

Data Set Citation
Dataset Originator/Creator: Steeves, Peter and Douglas Nebert
Dataset Title: Hydrologic units maps of the Conterminous United States
Dataset Release Date: 1994-01-01
Dataset Release Place: Reston, Virginia
Dataset Publisher: USGS
Data Presentation Form: maps
Online Resource: http://water.usgs.gov/lookup/getspatial?huc250k


Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA


Science Keywords
BIOSPHERE >TERRESTRIAL ECOSYSTEMS >WETLANDS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >DRAINAGE    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >HYDROPATTERN    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >LAKES    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >RIVERS/STREAMS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >TOTAL SURFACE WATER    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >WATER CHANNELS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >WATERSHED CHARACTERISTICS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >WETLANDS    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >WETLANDS


ISO Topic Category
BIOTA
GEOSCIENTIFIC INFORMATION
INLAND WATERS


Platform
MAPS    [Information]


Project
ESIP >Earth Science Information Partners Program    [Information]
NAWQA >National Water Quality Assessment Program    [Information]
C-MAP >Clean Air Mapping and Analysis Program    [Information]


Quality
The data produced by the Geographic Information Retrieval and Analysis System
(GIRAS) was originally collected at a scale of 1:250K. Some areas, notably
major cities in the west, were recompiled at a scale of 1:100K. In order to
join the data together and use the data in a geographic information system
(GIS) the data were processed in the ARC/INFO GUS software package. Within the
GIS, the data were edge matched and the neatline boundaries between maps were
removed to create a single data set for the conterminous United States.

In addition, quality control was performed via AMLs in ArcInfo, revisions were
made, and peer review was performed. See FGDC HYDRO metadata for more
information.

The data was originally obtained as digital versions of the 1:250,000 or
1:100,000 USGS quadrangles. The quadrangles were divided up into four regions
of the U.S. Maps were converted into ArcInfo coverages using AMLs.


Use Constraints
These data were digitized at a scale of 1:250,000 with some portions of
coverage at 1:100,000- and 1:2 million scale. Limitations of the data strictly
revolve around this scale input. Use of these boundaries with larger scale data
(i.e. 1:24k hydrography) is not recommended as it would be beyond the
resolution capabilities of the data set.


Keywords
GIS
Hydrologic Units
Regions
Rivers
Hydrology
Fresh Water
Drainage Basins


Data Set Progress
COMPLETE


Originating Center
USGS


Data Center
Clean Air Markets Division, U.S. Environmental Protection Agency    [Information]
Data Center URL: http://www.epa.gov/airmarkets/

Data Center Personnel
Name: EPA CLEAN AIR MARKETS DIVISION
Phone: 202-564-9180
Email: camdgis at epa.gov
Contact Address:
US EPA
Clean Air Markets Division
1200 Pennsylvania Avenue, NW
Mail Code 6204J
City: Washington
Province or State: DC
Postal Code: 20460
Country: USA


Water Resources Maps and GIS Information, Water Resources Division, U.S. Geological Survey, U.S. Department of the Interior    [Information]
Data Center URL: http://water.usgs.gov/lookup/getgislist

Data Center Personnel
Name: WATER WEBSERVER TEAM - USGS
Phone: 703-648-4000;1-800-426-9000
Email: h2oteam at usgs.gov
Contact Address:
USGS National Center
Water Resources Division
12201 Sunrise Valley Drive
City: Reston
Province or State: VA
Postal Code: 20192-0002
Country: USA



Data Center Personnel
Name: MARK NEGRI
Phone: 703-648-5613
Fax: 703-648-5295
Email: mnegri at usgs.gov
Contact Address:
12201 Sunrise Valley Drive, MS-445
City: Reston
Province or State: VA
Country: USA



Distribution
Distribution_Media: ftp
Distribution_Format: ArcInfo export format
Fees: No fees

Distribution_Media: ftp
Distribution_Format: SDTS
Fees: No fees


Personnel
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: 2002-11-21
Last DIF Revision Date: 2011-07-01


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