FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION
VERSION 2006

TITLE: DRASTIC VULNERABILITY AREAS OF THE FLORIDAN AQUIFER SYSTEM

Geodataset Name:        AQDRFL
Geodataset Type:        SHAPE
Geodataset Feature:     POLYGONS

GENERAL DESCRIPTION:

This coverage contains statewide DRASTIC data for the Floridan Aquifer System. DRASTIC is a system developed jointly by the U.S. Environmental Protection Agency (USEPA) and the National Water Well Association (NWWA) to map potential aquifer vulnerability to pollution introduced on the ground's surface.

DATA SOURCE(S):                  Florida Department of Environmental 
                                 Protection (FDEP) 
SCALE OF ORIGINAL SOURCE MAPS:   1:100,000
DATE OF AUTOMATION OR SOURCE:    April 1, 1998
GEODATASET EXTENT:   State of Florida, minus the following counties:
                     Broward, Charlotte, Collier, Dade, Desoto, Glades, 
                     Hardee, Hendry, Lee, Manatee, Martin, Monroe, 
                     Palm Beach, Sarasota, St. Lucie

FEATURE ATTRIBUTE TABLES
Datafile Name: AQDRFL.DBF

ITEM NAME      WIDTH      TYPE     PRECISION  
AREA             18     DECIMAL      5
PERIMETER        18     DECIMAL      5
AQDRFL_           5     DECIMAL      - 
AQDRFL_ID         5     DECIMAL      -
SETTING           3     CHARACTER    -
DW                2     DECIMAL      -
NR                2     DECIMAL      - 
AM                2     DECIMAL      -
SM                2     DECIMAL      -
T                 2     DECIMAL      -
IV                2     DECIMAL      -
HC                2     DECIMAL      - 
DWV               2     DECIMAL      -
NRV               2     DECIMAL      - 
AMV               2     DECIMAL      - 
SMV               2     DECIMAL      - 
TV                2     DECIMAL      -
IVV               2     DECIMAL      -
HCV               2     DECIMAL      -
INDEX             3     DECIMAL      -
DESCRIPT         64     CHARACTER    - 

FEATURE ATTRIBUTE TABLES CODES AND VALUES:

   ITEM      DESCRIPTION
   DRASTIC parameters and their associated weights:
   
   DW        Depth to Water  (Weight = 5)         
   NR        Net Recharge  (Weight = 4)
          
   AM        Aquifer Media  (Weight = 3)          
   SM        Soil Media  (Weight = 2)    
   T         Topography  (Weight = 1)     
        
   IV        Impact of Vadose Zone  (Weight = 5)
          
   HC        Hydraulic Conductivity  (Weight = 3)
          
   Weighted scores for DRASTIC parameters (= DRASTIC parameter value X weight)
   
   DWV       Weighted score of Depth to Water 
   NRV       Weighted score for Net Recharge
   AMV       Weighted score for Aquifer media
   SMV       Weighted score for Soil Media
 
   TV        Weighted score for Topography
   IVV       Weighted score for Impact of Vadose Zone
   HCV       Weighted score for Hydraulic Conductivity
   INDEX     INDEX = DRV + NRV + AMV + SMV + TV + IVV + HCV
   SETTING   Hydrogeologic Settingb (not scored) reflects general
             geomorphology and varies nationally by region.  Florida lies
             within region 11, the Southeast Coastal Plain, of the Ground
             water region of the United States as described by Heath in         
             USGS Water Supply Paper 2242. Four Settings predominate in
             region 11 and they are:
                11A  Karst limestone areas ( limestone near the surface)
                11B  Coastal Deposits (thick clastic marine sediments)
                11C  Swamps and Wetlands
                11D  Beaches and Bars (sandy coastal areas and relict
                     beach ridges)
                111  Not defined in original documentation;  probably a
                     typogragphic error.
   DESCRIPT  Based on SETTING

USER NOTES:

DRASTIC is a system developed jointly by the U.S. Environmental Protection Agency (USEPA) and the National Water Well Association (NWWA) to map potential aquifer vulnerability. The methodology utilizes existing hydrogeological information to produce color-coded maps which display areas that are more or less likely to be affected by pollution introduced on the ground's surface. These maps depict areas which are more or less sensitive to land use changes which may affect ground water quality.

Drastic maps are composites made up of eight individually mapped hydrogeological parameters. Seven of these parameters (depth to water -Dw, net recharge - Nr, aquifer media - Am, soil media - Sm, topography - T, impact of the vadose zone - Iv and hydraulic conductivity - Hc) are used to derive the DRASTIC summary index score. The eighth, hydrogeologic setting, is useful for general map interpretation but, it is not included in the summary index.

Drastic maps are most useful as a generalized tool to assess regional potential aquifer vulnerability. Except for soils and topography layers, the source maps used were regional, water management district or statewide in scale and scope of coverage. This precludes the use of DRASTIC maps as a site-specific tool for assessing potential aquifer vulnerability.

FGDL QUALITY ASSURANCE STATUS:

-Changed projection from datum HPGN to HPGN and from spheroid GRS1980 to Clark 1866.

-Tolerances were changed to FGDL standards.

-DESCRIPT item was added based on the item SETTING.

REFERENCES:

DATA LINEAGE SUMMARY:

A separate polygon coverage was built for each parameter and then the eight coverages were composited into a single coverage with all information from the originals for the FASTCAD drawings. These drawings were then converted to ARC/INFO coverages which were edited by county. The county coverages were then edgematched and mapjoined into a statewide coverage. The statewide coverages, for each aquifer, werethen dissolved for the individual DRASTIC parameters for further error checking of the composite coverages. Once all errors were corrected, the composite attributes were recalculated for the final statewide DRASTIC coverages.

    SOURCE TITLE :              Dw, Nr, Am, Sm, T, Iv, Hc  & Hydrogeologic
                                Setting   
    SCALE :                     1:100K except for Alachua County mapped at
                                1:24K                   
    DATUM :                     NAD 27                    
    MAP PROJECTION :            UTM-17           
    MEDIA OF SOURCE :           CAD DXF and Dbase Files
    CONDITION OF MEDIA :        Digital     
    DATE OF SOURCE MATERIAL :   Mid to Late 1980's
    UPDATE SCHEDULE :           None

CREATOR OF SOURCE OR DATA LAYER

    AGENCY/ORGANIZATION :       Florida Department of Environmental 
                                Protection
    UNIT/SECTION :              Ambient Monitoring   
    CONTACT PERSON :            Gary Maddox (source), Dave Adams (GIS)
    TITLE :                     Professional Geologist II, Environmental
                                Specialist II      
    PHONE NUMBER :              (850)921-9425, (850)414-8550

DERIVATION METHOD(S) FOR DATA

    PRE-AUTOMATION COMPILATION : Digitized by Water Management Districts
                                 (WMDs) except for SJRWMD done by Ambient
                                 Monitoring staff and Alachua County
                                 completed by the county    
    COMPUTER HARDWARE USED :     Sun Ultra 2 3D Creator              
    OPERATING SYSTEM :           UNIX                    
    DATABASE SOFTWARE AND VERSION USED :        Borland Dbase 5.5  
    GIS/MAPPING SOFTWARE AND VERSION USED :     ARC/INFO 7.1.1, ARC/View
                                                3.0a
    METHOD OF AUTOMATION :      Conversion of DXF to ARC/INFO coverage
    RESOLUTION OF AUTOMATION :  N/A     
    TOLERANCE OF DIGITIZER, SCANNER, ETC. : N/A
    INITIAL DATE OF AUTOMATION :     4/1/98       
    UPDATE SCHEDULE :           N/A                      
    SIZE OF DIGITAL FILE :              38,997,385
    FORMAT OF DIGITAL FILE :    ARC/INFO coverage
    CONTROL POINTS - 
    NAME OF COORDINATE SYSTEM USED : Varied by WMDs    
    
   This coverage was reprojected by the FGDL from datum HPGN to
   HPGN and from spheroid GRS1980 to Clark 1866 to comply with FGDL
   standards.

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:               Florida Department of Environmental Protection
Abbr.name:          FDEP
Phone:              850-414-8550
Web Site:           http://www.dep.state.fl.us
Contact Person:     
         Phone:     (850)921-9425, (850)414-8550

FGDL CONTACT:

Name:                   FLORIDA GEOGRAPHIC DATA LIBRARY
Abbr. Name:             FGDL
Address:                Florida Geographic Data Library
                        431 Architecture Building
                        PO Box 115706
                        Gainesville, FL  32611-5706
Web site:               http://www.fgdl.org

Contact FGDL:

      Technical Support:	        http://www.fgdl.org/fgdlfeed.html
      FGDL Frequently Asked Questions:  http://www.fgdl.org/fgdlfaq.html
      FGDL Mailing Lists:		http://www.fgdl.org/fgdl-l.html
      For FGDL Software:                http://www.fgdl.org/software.html