Metadata County Boundaries
Counties and County Equivalents Boundaries in the United States for BASINS
- Identification Information
- Spatial Reference Information
- Entity and Attribute Information
- Distribution Information
- Metadata Reference Information
- Text Version
- Identification_Information:
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- Citation:
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- Citation_Information:
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- Originator: U.S. Environmental Protection Agency/Office of Water/OST
- Publication_Date: 19980227
- Title:
- Counties and County Equivalents Boundaries in the United States for BASINS
- Publication_Information:
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- Publication_Place: Washington DC
- Publisher: US EPA
- Online_Linkage: Better Assessment Science Integrating Point and Non-point Sources (BASINS)
- Description:
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- Abstract:
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This coverage is of the county boundaries of the conterminous United States. It was derived from the U.S. Geological Survey State Boundaries, which were derived from Digital Line Graph (DLG) files representing the 1:2,000,000-scale map in the National Atlas of the United States.
- Purpose:
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This coverage is intended as a basemap for a variety of applications.
- Supplemental_Information:
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Limitations_of_Data: The original files for this map were provided in 15 sections. Boundaries near the edges of sections have been adjusted in edgematching.
Procedures: The BASINS data product was derived from the U.S. Geological Survey COUNTIES2M layer. The USGS procedures for that data product are followed by the BASINS procedures:
This series of maps was published as part of the National Atlas of the United States (USGS, 1970). The maps for the conterminous United States were digitized in 15 sheets and published in the Digital Line Graph (DLG) format as described by Domeratz and others (1983).
Each sheet was prepared by reading the DLG files of the political and water bodies layers, converting them to ARC/INFO, extracting the county boundaries and the coastline, respectively, and joining the two layers together. FIPS codes were assigned to all polygons using available sources, and were checked manually.
Boundaries with adjacent sheets of the 15-sheet set were edgematched manually, arbitrarily choosing one of the sheets as the "correct" border. Edgematching operations adjusted the linework as far as was necessary so that the coverages would fit to a tolerance of 100 meters. The coverage (referred to herein as Version 1.0) was stored as 49 separate coverages (48 states and the District of Columbia) because the ARC/INFO software in use at the time could not process the entire coverage. Individual states could be joined by specifying a tolerance of 100 meters.
From time to time, adjustments were made to the state coverages to reflect changes in U.S. counties. It is believed the accuracy of these adjustments is comparable to the original linework.
For Version 2.0, all state coverages were rejoined and manually edited to produce a perfect edgematch between all states. For states on the original map sheet boundaries, this adjustment averaged less than 20 meters and in no case was more than 100 meters. The whole coverage was CLEANed to a tolerance of 20 meters, which resulted in few, if any, effects on small offshore islands. The coverage also was checked to ensure that it represented current U.S. counties or county equivalents.
The coverage in Version 1.0 stopped at the coastline. There was no attempt to depict offshore areas. The created some problems when the coverage was used to assign county codes to sampling stations located near the coast. To help in this matter, Version 2.o includes offshore extensions of the county polygons. The (water) boundaries of many of these polygons are arbitrary.
The Canadian Great Lakes features are another new addition to Version 2.0. They were added to improve the utility of the coverage for visual displays. Although the Canadian Great Lakes are logically represented by a single polygon, practical considerations -- the inability of some software to plot polygons with a large number of vertices -- made it necessary to separate them into 4 polygons. The dividing lines are located in narrow channels to minimize interference with plotting patterns. Canadian islands within the Great Lakes also were included.
All tics were relocated to places that are easily visible on maps of the United States, to help in registering maps that may not otherwise have adequate registration information.
To expedite accessing parts of the coverage, certain items have been indexed with the procedure, index_county.aml. See Section 3 above. A spatial index also was created.
When using this coverage to clip or intersect other coverages, a tolerance as low as 2 meters can be used.
The processing used to derive this coverage moved boundaries from their positions on the original maps. In cases of conflicting lines, preference was given to forming the correct topology. Strictly speaking, this coverage is not identical to the source materials. These changes were unavoidable in producing a continuous coverage of the conterminous United States.
For revision 2.1, it was necessary to alter about 100 arcs. This was accomplished with ARCEDIT using the 1:100,000 TIGER county coverage as a background. These arcs were matched to the background so that they matched at least as close as other arcs that were not edited.
For distribution with BASINS v1.0, the national coverage was split into a series of coverages that included the spatial extent of each of the nine US EPA regions, plus the hydrologic accounting units that crossed Region boundaries. The nine regional coverages therefore overlapped at Regional boundaries. The coverages were distributed in PC ARC/INFO coverage format.
For distribution with Basins v2.0, the PA ARC/INFO coverages were exported on a PC then imported in workstation ARC/INFO v7.0.4. Each Regional coverage was then projected to geographic decimal degrees, NAD83. The coverages were then converted to ESRI Shapefile format, using the ARCSHAPE command.
Reviews_Applied: This coverage has received no formal review. It has, however, been used in numerous applications where serious errors would have been obvious. Some county coverages were corrected following such use. The offshore polygon extensions and the Canadian Great Lakes polygons have had no review.
BASINS v2.0 reviews: projected coverages were checked for topology. The shapefile format features and attributes were visually inspected and compared with the BASINS v1.0 PC ARC/INFO coverages.
Other_Related_Data_Sets: This coverage was derived from USGS 1:2,000,000-scale basemaps covering the United States.
References_Cited:
Negri, M. Digital map of state boundaries of the conterminous United States. 1994. U.S. Geological Survey, digital map.
Domeratz, M. A., Hallam, C. A., Schmidt, W. E., and Calkins, H. W., 1983. USGS Digital Cartographic Data Standards: Digital Line Graphs from 1:2,000,000-scale Maps. U.S. Geological Survey Circular 895-D, 38p.
U. S. Geological Survey, 1970. National atlas of the United States of America: Washington D.C., U. S. Geological Survey, 417p.
- Time_Period_of_Content:
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- Time_Period_Information:
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- Single_Date/Time:
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- Calendar_Date: 1994
- Currentness_Reference: publication date
- Status:
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- Progress: Complete
- Maintenance_and_Update_Frequency: None planned
- Spatial_Domain:
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- Bounding_Coordinates:
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- West_Bounding_Coordinate: -125.0000
- East_Bounding_Coordinate: -66.0000
- North_Bounding_Coordinate: 50.0000
- South_Bounding_Coordinate: 24.0000
- Keywords:
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- Theme:
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- Theme_Keyword_Thesaurus: None
- Theme_Keyword: County boundaries
- Place:
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- Place_Keyword_Thesaurus: Geographic Names Information System
- Place_Keyword: Conterminous United States of America (CONUS)
- Place_Keyword: Alabama AL
- Place_Keyword: Arizona AZ
- Place_Keyword: Arkansas AR
- Place_Keyword: California CA
- Place_Keyword: Colorado CO
- Place_Keyword: Connecticut CT
- Place_Keyword: Delaware DE
- Place_Keyword: District of Columbia DC
- Place_Keyword: Florida FL
- Place_Keyword: Georgia GA
- Place_Keyword: Idaho ID
- Place_Keyword: Illinois IL
- Place_Keyword: Indiana IN
- Place_Keyword: Iowa IA
- Place_Keyword: Kansas KS
- Place_Keyword: Kentucky KY
- Place_Keyword: Louisiana LA
- Place_Keyword: Maine ME
- Place_Keyword: Maryland MD
- Place_Keyword: Massachusetts MA
- Place_Keyword: Michigan MI
- Place_Keyword: Minnesota MN
- Place_Keyword: Mississippi MS
- Place_Keyword: Missouri MO
- Place_Keyword: Montana MT
- Place_Keyword: Nebraska NE
- Place_Keyword: Nevada NV
- Place_Keyword: New Hampshire NH
- Place_Keyword: New Jersey NJ
- Place_Keyword: New Mexico NM
- Place_Keyword: New York NY
- Place_Keyword: North Carolina NC
- Place_Keyword: North Dakota ND
- Place_Keyword: Ohio OH
- Place_Keyword: Oklahoma OK
- Place_Keyword: Oregon OR
- Place_Keyword: Pennsylvania PA
- Place_Keyword: Rhode Island RI
- Place_Keyword: South Carolina SC
- Place_Keyword: South Dakota SD
- Place_Keyword: Tennessee TN
- Place_Keyword: Texas TX
- Place_Keyword: Utah UT
- Place_Keyword: Vermont VT
- Place_Keyword: Virginia VA
- Place_Keyword: Washington WA
- Place_Keyword: West Virginia WV
- Place_Keyword: Wisconsin WI
- Place_Keyword: Wyoming WY
- Access_Constraints: None
- Use_Constraints: None
- Native_Data_Set_Environment:
- ArcView shapefiles for Windows 95 PC
- Spatial_Reference_Information:
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- Horizontal_Coordinate_System_Definition:
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- Geographic:
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- Latitude_Resolution: 0.0001
- Longitude_Resolution: 0.0001
- Geographic_Coordinate_Units: Decimal Degrees
- Geodetic_Model:
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- Horizontal_Datum_Name: North American Datum of 1983
- Ellipsoid_Name: Geodetic Reference System 80
- Semi-major_Axis: 6378137
- Denominator_of_Flattening_Ratio: 298.257
- Entity_and_Attribute_Information:
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- Detailed_Description:
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- Entity_Type:
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- Entity_Type_Label: CNTY.SHP
- Entity_Type_Definition: County polygon attributes
- Entity_Type_Definition_Source: USGS
- Attribute:
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- Attribute_Label: SHAPE
- Attribute_Definition: ArcView internal field
- Attribute_Definition_Source: Computed
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: Polygon
- Enumerated_Domain_Value_Definition: ArcView internal field
- Enumerated_Domain_Value_Definition_Source: Computed
- Attribute:
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- Attribute_Label: AREA
- Attribute_Definition: Area of polygon in square coverage units
- Attribute_Definition_Source: Computed
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: -
- Enumerated_Domain_Value_Definition: Area of polygon
- Enumerated_Domain_Value_Definition_Source: computed
- Attribute:
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- Attribute_Label: PERIMETER
- Attribute_Definition: Perimeter of polygon in coverage units
- Attribute_Definition_Source: Computed
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: Positive real numbers
- Enumerated_Domain_Value_Definition: Perimeter of polygon
- Enumerated_Domain_Value_Definition_Source: computed
- Attribute:
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- Attribute_Label: CNTY_
- Attribute_Definition: Internal feature number
- Attribute_Definition_Source: Computed
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: -
- Enumerated_Domain_Value_Definition: Internal feature number
- Enumerated_Domain_Value_Definition_Source: computed
- Attribute:
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- Attribute_Label: CNTY_ID
- Attribute_Definition: User-assigned feature number
- Attribute_Definition_Source: User-defined
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: -
- Enumerated_Domain_Value_Definition: User assigned feature number
- Enumerated_Domain_Value_Definition_Source: USEPA
- Attribute:
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- Attribute_Label: FIPS
- Attribute_Definition: County FIPS code
- Attribute_Definition_Source: FIPS
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: 01001-56999, none=0
- Enumerated_Domain_Value_Definition: County FIPS numeric code
- Enumerated_Domain_Value_Definition_Source: FIPS
- Attribute:
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- Attribute_Label: ST
- Attribute_Definition: 2 character state abbreviation
- Attribute_Definition_Source: FIPS
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: Two characters
- Enumerated_Domain_Value_Definition: State FIPS alphabetic code
- Enumerated_Domain_Value_Definition_Source: FIPS
- Attribute:
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- Attribute_Label: CNTYNAME
- Attribute_Definition: County name
- Attribute_Definition_Source: USGS GNIS
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: alphabetical
- Enumerated_Domain_Value_Definition: County name
- Enumerated_Domain_Value_Definition_Source: USGS
- Attribute:
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- Attribute_Label: PLYTYPE
- Attribute_Definition: Polygon type
- Attribute_Definition_Source: See Procedures
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: 0-4 and 9
- Enumerated_Domain_Value_Definition: Polygon type
- Enumerated_Domain_Value_Definition_Source: USGS
- Attribute:
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- Attribute_Label: WORKB
- Attribute_Definition: Basins Internal field
- Attribute_Definition_Source: USEPA
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: integer
- Enumerated_Domain_Value_Definition: Basins Internal Field
- Enumerated_Domain_Value_Definition_Source: USEPA
- Attribute:
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- Attribute_Label: STCOFIPS
- Attribute_Definition: State and county FIPS code
- Attribute_Definition_Source: FIPS
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: -
- Enumerated_Domain_Value_Definition: State and county FIPS code
- Enumerated_Domain_Value_Definition_Source: FIPS
- Attribute:
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- Attribute_Label: BEXT
- Attribute_Definition: Basins internal field
- Attribute_Definition_Source: USEPA
- Attribute_Domain_Values:
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- Enumerated_Domain:
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- Enumerated_Domain_Value: -
- Enumerated_Domain_Value_Definition: BASINS Internal field
- Enumerated_Domain_Value_Definition_Source: USEPA
- Distribution_Information:
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- Distributor:
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- Contact_Information:
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- Contact_Organization_Primary:
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- Contact_Organization: USEPA/Office of Water/OST
- Contact_Address:
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- Address_Type: Mailing Address
- Address: 1200 Pennsylvania Ave., NW (4305T)
- City: Washington
- State_or_Province: District of Columbia
- Postal_Code: 20460
- Country: USA
- Contact_Voice_Telephone: 202-566-0400
- Contact_Facsimile_Telephone: 202-566-0409
- Contact_Electronic_Mail_Address: [email protected]
- Distribution_Liability:
- Although these data have been processed successfully on a computer system at Tetra Tech, Inc., no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The U.S. Environmental Protection Agency nor Tetra Tech, Inc. shall not be held liable for improper or incorrect use of the data described and/or contained herein.
- Standard_Order_Process:
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- Digital_Form:
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- Digital_Transfer_Information:
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- Format_Name:
- Environmental Systems Research Institute (ESRI) ArcView Shapefile
- Digital_Transfer_Option:
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- Online_Option:
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- Computer_Contact_Information:
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- Network_Address:
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- Network_Resource_Name: Better Assessment Science Integrating Point and Non-point Sources (BASINS)
- Offline_Option:
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- Offline_Media: CD-ROM
- Recording_Format: ISO 9660
- Fees: None
- Ordering_Instructions:
- When requesting data by phone or mail, please inquire about spatial data sets that work with Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). The BASINS web page has instructions for downloading datasets. It also has a link to The National Center for Environmental Publications and Information (NCEPI), from which BASINS CD-ROMs may be ordered. Each CD-ROM contains the BASINS v2.0 Application and this data set along with others covering the spatial extent of an EPA Region.
- Metadata_Reference_Information:
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- Metadata_Date: 20070611
- Metadata_Contact:
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- Contact_Information:
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- Contact_Organization_Primary:
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- Contact_Organization: USEPA/OW/OST
- Contact_Address:
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- Address_Type: Mailing Address
- Address: 1200 Pennsylvania Ave., NW (4305T)
- City: Washington
- State_or_Province: District of Columbia
- Postal_Code: 20460
- Country: USA
- Contact_Voice_Telephone: 202-566-0400
- Contact_Facsimile_Telephone: 202-566-0409
- Contact_Electronic_Mail_Address: [email protected]
- Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
- Metadata_Standard_Version: 19940608
Generated by mpon Wed Sep 09 11:05:50 1998