FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION
VERSION 2006

TITLE: USGS 1:24,000 HYDROGRAPHY - LINES

Geodataset Name:    HY24L
Geodataset Type:    SHAPE
Geodataset Feature: LINE

GENERAL DESCRIPTION:

This dataset contains Hydrological Line Features from the USGS 1:24000 scale DLG's.
The dataset has been updated from the previous version on FGDL 3.0. 
DATA SOURCE(S):                   United States Geological Survey
SCALE OF ORIGINAL SOURCE MAPS:    1:24,000
DATE OF AUTOMATION OR SOURCE:     Ongoing
GEODATASET EXTENT:                State of Florida
 

FEATURE ATTRIBUTE TABLES:

Datafile Name: HY24L.DBF

ITEM NAME            WIDTH   TYPE       PRECISION  

SHAPE                  9     Line           0
DESC1                 50     CHARACTER      -
DESCRIPT              50     CHARACTER      -  
 

FEATURE ATTRIBUTE TABLES CODES AND VALUES:

ITEM            ITEM DESCRIPTION 
                    
SHAPE           Data attribute inherent to the ESRI shapefile format,
                which defines the data as a point, polyline, or polygon
                
DESC1           Description based on Major1/Minor1                                              

DESCRIPT        FGDL added item, based on the major/minor pair that is 
		most descriptive
 

USER NOTES:

This data set comes from the USGS revised DLG ftp site. There are two hydrography datasets: HY24P and HY24L. Hy24P has polygon features and HY24L has line features.

The DLG's were converted to coverage format, processed, then converted to shapefile. The following items were removed from the attribute table: Major1, Minor1, Major2, Minor2, Major3, Minor3, Major4, Minor4, Major5, Minor5, Phot_rev, Surf_ft, Surf_m, Below_m, Angle, Riv_mile, Position, Coinc_ft, Desc2, Desc3, Desc4, Desc5. These items were removed for ease of querying the database since most records contained no values for these items. The items Desc1, Desc2, Desc3, Desc4, and Desc5 are verbal descriptions which correspond to the Major/Minor code pairs. GeoPlan added the 'DESCRIPT' item based on DESC1-DESC5 to represent the value that was most descriptive.

A note concerning data scale:

Scale is an important factor in data usage. Certain scale datasets are not suitable for some project, analysis, or modelling purposes. Please be sure you are using the best available data.

1:24000 scale datasets are recommended for projects that are at the county level. 1:24000 data should NOT be used for high accuracy base mapping such as property parcel boundaries.

1:100000 scale datasets are recommended for projects that are at the multi-county or regional level.

1:250000 scale datasets are recommended for projects that are at the regional or state level or larger.

Vector datasets with no defined scale or accuracy should be considered suspect. Make sure you are familiar with your data before using it for projects or analyses. Every effort has been made to supply the user with data documentation. For additional information, see the References section and the Data Source Contact section of this documentation. For more information regarding scale and accuracy, see our web pages at: http://www.geoplan.ufl.edu/education.html

This dataset has been updated from the previous version on FGDL 3.0.

FGDL QUALITY ASSURANCE STATUS:

-Converted from dlg to coverage
-Separated utm zone 16 from utm zone 17
-Mapjoined 16's and 17's with net option
-Used aml to joinitem pcode values to .pat and acode to .aat
-Added major and minor codes up to five in order to ensure proper mapjoin
-Build with poly option
-Set tolerances with settol then increased fuzzy to 2
-Dropfeatures line for coverage
-Dissolve to get rid of extraneous boundary lines
-Alter fields to make sure that they are not over 10 characters
-Set Tolerances to FGDL Standards
-Set Precision to Double
-Upcased Fields that had lower case characters 
-Added DESCRIPT item based on the major/minor pair that is most descriptive 
-Removed all items except Desc1 and Descript
-Converted to Shapefile

REFERENCES:

UNITED STATES GEOLOGICAL SURVEY (USGS)

DATA LINEAGE SUMMARY:

The data was downloaded by the GeoPlan Center from the USGS DLG ftp site. The files were orginally in DLG format. The source projection was UTM (zone 16 and 17) units - meters datum - Nad27 and spheroid - Clarke 1866.

MAP PROJECTION PARAMETERS


  Projection                           ALBERS
  Units                                METERS
  Datum                                HPGN
  Spheroid                             GRS1980
  1st standard parallel                24   0  0.000
  2nd standard parallel                31  30  0.000
  central meridian                    -84   0  0.000
  latitude of projection's origin      24   0  0.000 
  false easting (meters)               400000.00000
  false northing (meters)              0.00000

DATA SOURCES CONTACT(S):

Name:                UNITED STATES GEOLOGICAL SURVEY
Abbr. name:          USGS 
Address:             USGS Mapping Applications Center
                     National Cartographic Info Center
                     507 National Center
                     Reston VA 22092
Phone:               (703) 8606045 
Fax:                 (703) 6484165
Web site:            http://www.usgs.gov
Email:               MACWEBMASTER@USGS.GOV
Contact Person:      They will route your message to the person best
                     qualified to respond.

FGDL CONTACT:

Name:			Florida Geographic Data Library
Abbr. Name:		FGDL
Address:		Florida Geographic Data Library
                        431 Architecture
                        PO Box 115706
                        Gainesville, FL  32611-5706
Web site:               http://www.fgdl.org
Contact FGDL:
      Technical Support:	        http://www.fgdl.org/fgdl/fgdlfeed.html
      FGDL Frequently Asked Questions:  http://www.fgdl.org/fgdl/fgdlfaq.html
      FGDL Mailing Lists:	        http://www.fgdl.org/fgdl/fgdl-l.html
      For FGDL Software:                http://www.fgdl.org/fgdl/software.html