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