FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION
VERSION 2006
TITLE: DRASTIC COVERAGE OF INTERMEDIATE AQUIFER SYSTEM
Geodataset Name: AQDRIN Geodataset Type: SHAPE Geodataset Feature: POLYGON
GENERAL DESCRIPTION:
This dataset contains DRASTIC coverage for the Intermediate 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. 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.
DATA SOURCE(S): Florida Department of Environmental Protection (FDEP) SCALE OF ORIGINAL SOURCE MAPS: 1:100,000 DATE OF AUTOMATION OR SOURCE: 07/07/98 GEODATASET EXTENT: The following Florida counties: Hamilton, Suwannee, Colombia, Union, Bradford, Polk, Manatee, Hillsborough, Hardee, Sarasota, DeSoto, and Charlotte.
FEATURE ATTRIBUTE TABLES:
Datafile Name: AQDRIN.DBF ITEM NAME WIDTH TYPE PRECISION SHAPE 8 SHAPEPOLY 0 AREA 23 DECIMAL 5 PERIMETER 23 DECIMAL 5 SETTING 3 CHARACTER - DW 2 SHORT - NR 2 SHORT - AM 2 SHORT - SM 2 SHORT - T 2 SHORT - IV 2 SHORT - HC 2 SHORT - DWV 2 SHORT - NRV 2 SHORT - AMV 2 SHORT - SMV 2 SHORT - TV 2 SHORT - IVV 2 SHORT - HCV 2 SHORT - INDEX_X 3 SHORT - DESCRIPT 64 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.
AREA Area of the polygon feature (meters)
PERIMETER Perimeter of polygon feature (meters)
SETTING Hydrogeologic setting, 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)
DW depth to water 5
NR net recharge 4
AM aquifer media 3
SM soil media 2
T topography 1
IV impact of vadose zone 5
HC hydraulic conductivity 3
DWV Dw depth to water multiplied by 5
NRV Nr net recharge multiplied by 4
AMV Am aquifer media multiplied by 3
SMV Sm soil media multiplied by 2
TV T topography multiplied by 1
IVV Iv impact of vadose zone multiplied by 5
HCV Hc hydraulic conductivity multiplied by 3
INDEX_X (Drv+ Nrv + Amv + Smv + Tv + Ivv + Hcv)
DESCRIPT FGDL added item based on SETTING.
Looks good
USER NOTES:
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. The dataset provides location and attribute information for use in national and regional cartographic and network analysis applications. 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
FGDL QUALITY ASSURANCE STATUS:
-Added DESCRIPT item based on SETTING
REFERENCES:
Florida Department of Environmental Protection (FDEP) http://www.dep.state.fl.us/gis/datadir.asp
DATA LINEAGE SUMMARY:
Geoplan downloaded this dataset from the Florida DEP website.
http://www.dep.state.fl.us/gis/datadir.asp
The dataset's prior history from FDEP is as follows:
DESCRIPTION OF SOURCE MATERIAL(S)
A separate polygon coverage was built for each parameter (depth to water - Dw,
net recharge - Nr, aquifer media - Am, soil media - Sm, topography - T,
impact of the vadose zone - Iv, hydraulic conductivity - Hc, hydrogeologic setting).
Then, the eight coverages were composited into a single coverage with all of the 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, were then 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 : 04/01/98
UPDATE SCHEDULE : N/A
SIZE OF DIGITAL FILE : 5,518,034
FORMAT OF DIGITAL FILE : ARC/INFO coverage
CONTROL POINTS -
EXPLANATION OF PROCEDURES USED TO TRANSFORM THE DATA
The original county CAD DRASTIC drawings were converted to ARC/INFO files, built
as point, line and polygon coverages and edited for digitizing errors. The
Dbase files containing the attribute data were then joined to polygon attribute
tables in ARC/INFO. County coverages were then edgematched and mapjoined to
create a statewide coverage. The statewide coverage was then projected to
Albers HPGN and dissolved on the individual DRASTIC parameters and edited for
county boundary discrepancies. The dissolved layers were intersected back
together, the weighted fields were calculated and summed to produce the final
DRASTIC Index values which were then used to color, according to prescribed
ranges, the final coverage.
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
Contact Person: GIS Section/GIS Help Desk
Phone: 850/921-9745
Web site: http://www.dep.state.fl.us/gis/
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/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