Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Clawges, Rick
        Originator: Price, Curtis
        Publication_Date: 1999
        Title: Ground-water regions of the conterminous United States
        Edition: 1.0
        Geospatial_Data_Presentation_Form: map
        Publication_Information:
          Publication_Place: Rapid City, SD
          Publisher: U.S. Geological Survey
        Series_Information:
          Series_Name: Open-File Report
          Issue_Identification: 99-77
        Online_Linkage:
          http://water.usgs.gov/lookup/getspatial?ofr99-77_gwregion

    Description:
      Abstract:

        This data set describes ground-water regions in the United
        States defined by the U.S. Geological Survey.  These
        ground-water regions are useful for dividing the United States
        into areas of roughly similar hydrologic characterstics and
        water-use patterns. These regions are very generalized and
        were developed from a illustration published at a scale of
        approximately 1:20 million.

      Purpose:

        This data set is a generalized representation of ground-water
        areas in the United States and was created for use in the
        analysis of ground-water quality data on volatile organic
        compounds (VOCs) by the U.S. Geological Survey (USGS) National
        Water-Quality Assessment Program (NAWQA) VOC National
        Synthesis Team. Polygons from this data set were used with
        common ranges of hydraulic characteristics provided in the
        Entity_and_Attribute_Overview below to relate ground-water
        resources with NAWQA study areas on a broad scale.

      Supplemental_Information:

        One source map for this data set is figure 12, from p. 17 
        of Heath (1984).

        Coastlines and political boundaries are modified from a digital
        version of U.S. Geological Survey 1:2,000,000 county boundaries 
        (USGS, 1984).

        REVIEWS APPLIED TO DATA

        This electronic report was subjected to the same review standard
        that applies to all U.S. Geological Survey reports. Reviewers
        were asked to check the topological consistency, tolerances,
        attribute frequencies and statistics, projection, and geographic
        extent. Reviewers were given a paper copy of the map from p. 17
        of Heath (1984) along with the digital data set to verify the
        linework and attributes. The reviewers checked the metadata and
        a_readme.1st files for completeness and accuracy.

        RELATED SPATIAL AND TABULAR DATA SETS

        The data set GWREGUW is similar to this data set (GWREGION)
        but also contains polygons for unconsolidated watercourses
        taken from the AQUIF75M data set from the National Atlas of
        the United States (U.S. Geological Survey, 1970).

        REFERENCES CITED

        Environmental Systems Research Institute, Inc. (ESRI), 1997,
        Arc/INFO 7.1.1 Help, Redlands, California, [on-line documentation].

        Heath, R.C., 1984, Ground-Water Regions of the United States: U.S.
        Geological Survey Water-Supply Paper 2242, 78 p.

        Lanfear, K.J., 1984, Digital map of counties and county equivalents 
        in the conterminous United States: U.S. Geological Survey data
        available on the World Wide Web, accessed July 21, 1998, at
        URL http://water.usgs.gov/lookup/getspatial?county2m

        U.S. Geological Survey, 1970, The National Atlas of the United States
        of America, Washington, D.C., U.S. Government Printing Office, 417 p.

        NOTES

        The accuracy of this data set is extremely limited. No map
        projection or registration points were included in the source
        map (figure 12 from Heath (1984)). The map projection appeared
        to be Albers Conical Equal Area, so an Albers-projected
        data set of U.S. states was used to define registration points
        between a scanned image of the figure and the state boundary
        linework.

        Any use of trade, product, or firm names is for descriptive
        purposes only and does not imply endorsement by the
        U.S. Government.

        Although this data set has been used by the U.S. Geological
        Survey, U.S. Department of the Interior, no warranty expressed
        or implied is made by the U.S. Geological Survey as to the
        accuracy of the data and related materials.

        The act of distribution shall not constitute any such
        warranty, and no responsibility is assumed by the
        U.S. Geological Survey in the use of this data, software, or
        related materials.

        Although this Federal Geographic Data Committee-compliant
        metadata file is intended to document the data set in
        nonproprietary form, as well as in ARC/INFO format, this
        metadata file may include some ARC/INFO-specific terminology.

    Time_Period_of_Content:
      Time_Period_Information:
        Single_Date/Time:
          Calendar_Date: 1984
      Currentness_Reference:
        The data is based on the map in Heath's
        report published in 1984.

    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: None planned.

    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: -127.84205584
        East_Bounding_Coordinate: -65.40873623
        North_Bounding_Coordinate: 48.1924194
        South_Bounding_Coordinate: 23.25354341
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: None
        Theme_Keyword: ground water
        Theme_Keyword: region
        Theme_Keyword: aquifer
      Place:
        Place_Keyword_Thesaurus: None
        Place_Keyword: Conterminous 48 United States
    Access_Constraints: None
    Use_Constraints: None

    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Curtis V. Price
          Contact_Organization: U.S. Geological Survey
        Contact_Position: Physical Scientist
        Contact_Address:
          Address_Type: mailing address
          Address: 1608 Mountain View Rd
          City: Rapid City
          State_or_Province: South Dakota
          Postal_Code: 57702
          Country: United States of America
        Contact_Voice_Telephone: (605) 355-4560
        Contact_Facsimile_Telephone: (605) 355-4523
        Contact_Electronic_Mail_Address: cprice@usgs.gov
        Contact_Instructions: none

    Data_Set_Credit:

      Compilation of the data sets was supported by the National
      Water-Quality Assessment (NAWQA) Program of the U.S. Geological
      Survey. The objectives of the NAWQA Program are to: (1) describe
      current water-quality conditions for a large part of the
      Nation's freshwater streams, rivers, and aquifers, (2) describe
      how water quality is changing over time, and (3) improve the
      understanding of the primary natural and anthropogenic factors
      that affect water-quality conditions. National analysis of data,
      based on aggregation of comparable information obtained from
      across the United States, is a major component of the NAWQA
      Program. These data sets were created in support of NAWQA
      national data analysis activities.

    Security_Information:
      Security_Classification_System: Public
      Security_Classification: Unclassified
      Security_Handling_Description: None

    Native_Data_Set_Environment: Operating System: 

      dgux, 5.4R3.10, AviioN UNIX, ARC/INFO version 7.1.1
        
    Cross_Reference:
      Citation_Information:
        Originator: Clawges, Rick, and Price, Curtis
        Publication_Date: 1998
        Title:
          Ground-water regions of the conterminous United States with
          unconsolidated watercourses
        Edition: 1.0
        Geospatial_Data_Presentation_Form: map
        Publication_Information:
          Publication_Place: Rapid City, SD
          Publisher: U.S. Geological Survey
        Online_Linkage: http://water.usgs.gov/lookup/getspatial?ofr99-77_gwreguw
        Larger_Work_Citation
          Citation_Information:
            Originator: Clawges, Rick and Price, Curtis
            Publication_Date: 1999
            Title: 
              Digital data sets describing principal aquifers, 
              surficial geology, and ground-water regions of the 
              conterminous United States
            Edition: 1.0
            Series_Information:
              Series_Name: Open-File Report
              Issue_Identification: 99-77
            Publication_Information:
              Publication_Place: Rapid City, SD
              Publisher: U.S. Geological Survey
            Online_Linkage: http://water.usgs.gov/pubs/ofr/ofr99-77/index.html

  Data_Quality_Information:
    Logical_Consistency_Report: Polygon and chain-node topology present.

    Completeness_Report:

      This data set includes all of the ground-water region boundaries
      presented on Figure 12 on p. 17 of Heath (1984).

    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report:
          No tests performed, except a visual check to see how well the data set
          lines corresponded to those on the paper map.

    Lineage:
      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Ralph C. Heath
            Publication_Date: 1984
            Title: Ground-Water Regions of the United States
            Geospatial_Data_Presentation_Form: map
            Series_Information:
              Series_Name: USGS Water Supply Paper
              Issue_Identification: 2242
            Publication_Information:
              Publication_Place: Reston, VA
              Publisher: U.S. Geological Survey
        Source_Scale_Denominator: 20000000
        Type_of_Source_Media: paper
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 1984
          Source_Currentness_Reference: publication date
        Source_Citation_Abbreviation: none
        Source_Contribution: 
          Ground-water region polygon boundaries from Fig. 12
          on page 17 of the report.
        
      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Lanfear, K.J.
            Publication_Date: 19840816
            Title: 
              Counties and county equivalents in the
              conterminous United States
            Geospatial_Data_Presentation_Form: map
            Publication_Information:
              Publication_Place: Reston, Virginia, USA
              Publisher: U.S. Geological Survey
            Online_Linkage: http://water.usgs.gov/lookup/getspatial?county2m
        Type_of_Source_Media: online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 19840816
          Source_Currentness_Reference: as of 1983
        Source_Citation_Abbreviation: county2m
        Source_Contribution: US boundary and coastlines

      Process_Step:
        Process_Description:
        
          The source map was scanned to produce an image file. ARC/INFO
          software and commands (Environmental Systems Research
          Institute, Inc., 1997) were used to convert the image file
          to a coverage.  ARC/INFO commands and modules are shown
          below in capitals.
  
          Step 1.  Converted image to a grid using IMAGEGRID command.
  
          Step 2.  Used GRID functions to select only grid cells
          corresponding to ground-water region boundaries. This was done
          using geometric functions.
  
          Step 3.  Raster to vector conversion using GRIDLINE command.
  
          Step 4.  Edited line coverage using ARCEDIT module.  Removed
          dangles, added and deleted arcs.
  
          Step 5. Transformed coordinate data from inches to Albers
          Conical Equal Area, North American Datum of 1927 (NAD27) using
          TRANSFORM command.  CONTROLPOINTS command was used to register
          points on the image to points on the coverage
          /home/vocgis/lib/pol/stategen. Details of CONTROLPOINTS:
  
          >Scale (X,Y) = (683001.735,672871.472)  Skew (degrees) = (-0.139)
          >Rotation (degrees) = (-0.627)  Translation = (-2725624.058,9074340.876)
          >RMS Error (input,output) = (0.033,22644.965)
  
          Added United States boundary using
          coverage /home/vocgis/lib/pol/stategen, which is a generalized version
          of county2m coverage.
  
          Step 6.  Used CLEAN to build polygon topology.
                   Used fuzzy tolerance of 1.0 and dangle length of 0.
  
          Step 7. Added attribute features to polygons.
  
        Process_Date: 19970606

      Process_Step:
        Process_Description:

          Step 8. GENERALIZEd coverage with a weed tolerance of 1000 meters
          using the POITREMOVE method for line generalization. Rebuilt topology.

        Process_Date: 19981026

      Process_Step:
        Process_Description:

          Step 9. Used UNSPLIT in Arcedit to remove unnecessary pseudo nodes.

          Step 10. Rebuild topolgy

          Step 11. Copied coverage from DOUBLE to SINGLE precision and CLEANed.
                   Used fuzzy tolerance of 1.0 and dangle length of 0.
   
          Step 12. Used RENODE to sequentially number nodes.

        Process_Date: 19981028

  
  Spatial_Data_Organization_Information:
    Direct_Spatial_Reference_Method: Vector
    Point_and_Vector_Object_Information:
      SDTS_Terms_Description:
        SDTS_Point_and_Vector_Object_Type: Point
        Point_and_Vector_Object_Count: 34
      SDTS_Terms_Description:
        SDTS_Point_and_Vector_Object_Type: String
        Point_and_Vector_Object_Count: 78
      SDTS_Terms_Description:
        SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
        Point_and_Vector_Object_Count: 35

  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Planar:
        Map_Projection:
          Map_Projection_Name: Albers Conical Equal Area
          Albers_Conical_Equal_Area:
            Standard_Parallel: 29.5
            Standard_Parallel: 45.5
            Longitude_of_Central_Meridian: -96
            Latitude_of_Projection_Origin: 23
            False_Easting: 0.00000
            False_Northing: 0.00000
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: coordinate pair
          Coordinate_Representation:
            Abscissa_Resolution: 1.0
            Ordinate_Resolution: 1.0
          Planar_Distance_Units: METERS
      Geodetic_Model:
        Horizontal_Datum_Name: North American Datum of 1927
        Ellipsoid_Name: Clarke 1866
        Semi-major_Axis: 6378206.4
        Denominator_of_Flattening_Ratio: 294.98

  Entity_and_Attribute_Information:
    Overview_Description:
      Entity_and_Attribute_Overview:

        There are two attribute files associated with this data set.

        An arc attribute table:

        >DATAFILE NAME: GWREGION.AAT
        >8 ITEMS: STARTING IN POSITION    1
        > COL  ITEM NAME         WDTH OPUT TYP N.DEC  ALTERNATE NAME
        >01  FNODE#              4    5  B    -
        >05  TNODE#              4    5  B    -
        >09  LPOLY#              4    5  B    -
        >13  RPOLY#              4    5  B    -
        >17  LENGTH              8   18  F    5
        >25  GWREGION#           4    5  B    -
        >29  GWREGION-ID         4    5  B    -
        >33  USBND               1    1  I    -

        FNODE# is the internal number of the from-node

        TNODE# is the internal number of the to-node

        LPOLY# is the internal number of the polygon to the left of the arc

        RPOLY# is the internal number of the polygon to the right of the arc

        LENGTH is the length of the arc in meters

        GWREGION# is a program-generated feature identity number

        GWREGION-ID is a user-assigned feature identity number

        USBND is an item used to indicate if the arc is on the
        boundary of the United States. Arcs representing the United
        States boundary are flagged USBND = 1, others are coded
        USBND = 0.

        There also is a polygon attribute table associated with this data set:

        >DATAFILE NAME: GWREGION.PAT
        >6 ITEMS: STARTING IN POSITION    1
        >COL  ITEM NAME         WDTH OPUT TYP N.DEC  ALTERNATE NAME
        >01  AREA                8   18  F    5
        >09  PERIMETER           8   18  F    5
        >17  GWREGION#           4    5  B    -
        >21  GWREGION-ID         4    5  B    -
        >25  CODE                2    2  I    -
        >27  DESC               40   40  C    -

        AREA is the area of the polygon in square meters

        PERIMETER is the perimeter of the polygon in meters

        GWREGION# is a program-generated feature identity number

        GWREGION-ID is a user-assigned feature identity number 

        CODE is the region number with values as shown in the table
        from Heath (below). A CODE of 99 has been added for water
        areas.

        DESC is the region name from the same table. "WATER" in this
        item indicates a water body.

        Heath (1984) also designates ground water regions 12 (alluvial
        valleys), 13 (Hawaiian islands), 14 (Alaska), and (15) Puerto
        Rico/Virgin Islands. These areas are not included in this data
        set, however, alluvial valleys is included in the data set
        "gwreguw", which is provided on this CD.

        A modified version of Table 6 from p. 19 of Heath (1984) is
        provided below. This table contains common ranges on the
        hydraulic characteristics of ground-water regions of the
        United States.

        >Region
        >number   Region name                         Geologic situation
        >-----------------------------------------------------------------------------------
        >
        > 1       Western mountain ranges.............Mountains with thin soils over
        >                                             fractured rocks, alternating with
        >                                             narrow alluvial, and, in part,
        >                                             glaciated valleys
        > 2       Alluvial basins.....................Thick (an average thickness of about
        >                                             5m was used as the breakpoint between
        >                                             thick and thin) alluvial (locally
        >                                             glacial) deposits in basins and
        >                                             valleys bordered by mountains
        > 3       Columbia lava plateau...............Thick sequence of lava flows inter-
        >                                             bedded with unconsolidated deposits
        >                                             and overlain by thin soils
        > 4       Colorado plateau and Wyoming basin..Thin (an average thickness of about
        >                                             5m was used as the breakpoint between
        >                                             thick and thin) soils over fractured
        >                                             sedimentary rocks
        > 5       High Plains.........................Thick alluvial deposits over frac-
        >                                             tured sedimentary rocks
        > 6       Nonglaciated central region.........Thin regolith over fractured sedi-
        >                                             mentary rocks
        > 7       Glaciated central region............Thick glacial deposits over fractured
        >                                             sedimentary rocks
        > 8       Piedmont and Blue Ridge.............Thick regolith over fractured crystal-
        >                                             line and metamorphosed sedimentary
        >                                             rocks
        > 9       Northeast and Superior uplands......Thick glacial deposits over fractured
        >                                             crystalline rocks
        >10       Atlantic and Gulf Coastal Plain.....Complexly interbedded sands, silts,
        >                                             and clays
        >11       Southeast Coastal Plain.............Thick layers of sand and clay over
        >                                             semiconsolidated carbonate rocks
        >
        >
        >      Transmissivity     Hydraulic cond.      Recharge rate          Well yield
        >Reg.    sq. m / day           m / day              mm / yr         cub. m / min
        >-------------------------------------------------------------------------------
        >1           -     100    0.0003 -     15       3     -    50        0.04 -  0.4
        >2      20   -  20,000   30      -    600       0.03  -    30        0.4  - 20
        >3   2,000   - 500,000  200      -  3,000       5     -   300        0.4  - 80
        >4       0.5 -     100    0.003  -      2       0.3   -    50        0.04 -  2
        >5   1,000   -  10,000   30      -    300       5     -    80        0.4  - 10
        >6     300   -  10,000    3      -    300       5     -   500        0.4  - 20
        >7     100   -   2,000    2      -    300       5     -   300        0.2  -  2
        >8       9   -     200    0.001  -      1      30     -   300        0.2  -  2
        >9      50   -     500    2      -     30      30     -   300        0.1  -  1
        >10    500   -  10,000    3      -    100      50     -   500        0.4  - 20
        >11  1,000   - 100,000   30      -  3,000      30     -   500        4    - 80

        Abbreviations:

        >Reg.  - Ground water region number
        >cond. - conductivity
        >sq.   - square
        >m     - meter
        >mm    - millimeter
        >yr    - year
        >cub.  - cubic
        >min   - minute

      Entity_and_Attribute_Detail_Citation: None

  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Water Webserver Team
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: Mailing address
          Address: 12201 Sunrise Valley Drive, MS 440
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Electronic_Mail_Address: h2oteam@qvarsx.er.usgs.gov
        Contact_Voice_Telephone: (800) 426-9000
        Contact_Instructions: Contact via email
    Distribution_Liability: 

      Although this data set has been used by the U.S. Geological
      Survey, U.S. Department of the Interior, no warranty expressed
      or implied is made by the U.S. Geological Survey as to the
      accuracy of the data and related materials.

      The act of distribution shall not constitute any such warranty,
      and no responsibility is assumed by the U.S. Geological Survey
      in the use of this data, software, or related materials.

  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Branch of Information Services
          Contact_Organization: U.S. Geological Survey
        Contact_Position: Branch of Information Services
        Contact_Address:
          Address_Type: mailing address
          Address: Box 25286
          City: Denver Federal Center
          State_or_Province: Colorado
          Postal_Code: 80225-0286
          Country: United States of America
        Contact_Voice_Telephone: (303) 202-4210
        Hours_of_Service: 8 AM to 4 PM Mountain Time Zone, Monday through Friday
    Distribution_Liability: 

      Although this data set has been used by the U.S. Geological
      Survey, U.S. Department of the Interior, no warranty expressed
      or implied is made by the U.S. Geological Survey as to the
      accuracy of the data and related materials.

      The act of distribution shall not constitute any such warranty,
      and no responsibility is assumed by the U.S. Geological Survey
      in the use of this data, software, or related materials.

    Resource_Description: CD-ROM
  Metadata_Reference_Information:
    Metadata_Date: 19981016
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Rick Clawges and Curtis Price
          Contact_Organization: USGS NAWQA VOC National Synthesis
        Contact_Address:
          Address_Type: Mailing address
          Address: 1608 Mountain View Rd
          City: Rapid City
          State_or_Province: SD
          Postal_Code: 57702
          Country: USA
        Contact_Electronic_Mail_Address: rclawges@usgs.gov,cprice@usgs.gov
        Contact_Voice_Telephone: (605) 355-4560
        Contact_Instructions: Contact via email
    Metadata_Standard_Name: 
      FGDC Content Standards for Digital Geospatial Metadata ("CSDGM version 2")
    Metadata_Standard_Version: FGDC-STD-001-1998