DRASTIC model results for Upper Floridan aquifer vulnerability to Bromacil and Ethylene Dibromide

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Frequently anticipated questions:

What does this data set describe?

Title:
DRASTIC model results for Upper Floridan aquifer vulnerability to Bromacil and Ethylene Dibromide
Abstract:
This dataset includes DRASTIC (Aller and others, 1987) model results for Upper Floridan aquifer vulnerability to contamination. The DRASTIC value serves as an intrinsic vulnerability index for assessing the transport of contaminants from the surface. The DRASTIC model setup requires the input of raster data for depth to groundwater, aquifer recharge, aquifer media, soil media, topography, vadose zone media, and aquifer hydraulic conductivity. These variables were entered into the DRASTIC equation using the raster calculator tool in ArcGIS.
Supplemental_Information:
A downloadable version of the final dataset is provided in GeoTIFF file format with 10-meter resolution.
  1. How might this data set be cited?
    Douglas, Steven H., 20170828, DRASTIC model results for Upper Floridan aquifer vulnerability to Bromacil and Ethylene Dibromide: U.S. Geological Survey data release doi:10.5066/F7S46QTV, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -83.252177
    East_Bounding_Coordinate: -80.829948
    North_Bounding_Coordinate: 29.695895
    South_Bounding_Coordinate: 26.572896
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2017
    Currentness_Reference:
    publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster digital data-set
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 19854 x 32323, type Grid Cell
    2. What coordinate system is used to represent geographic features?
      The map projection used is USA_Contiguous_Albers_Equal_Area_Conic_USGS_version.
      Projection parameters:
      Standard_Parallel: 29.5
      Standard_Parallel: 45.5
      Longitude_of_Central_Meridian: -96.0
      Latitude_of_Projection_Origin: 23.0
      False_Easting: 0.0
      False_Northing: 0.0
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 10.0
      Ordinates (y-coordinates) are specified to the nearest 10.0
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    drastic_model.tif
    GeoTIFF file that includes DRASTIC model results for the Upper Floridan aquifer vulnerability to contamination. (Source: USGS)
    OID
    Internal feature number. Sequential unique whole numbers that are automatically generated. (Source: Esri)
    Range of values
    Minimum:0
    Maximum:4
    Value
    DRASTIC reclassified vulnerability class values. 1 = Very Low Vulnerability, 2 = Low, 3 = Medium, 4 = High, 5 = Very High. (Source: USGS)
    ValueDefinition
    1Very Low Vulnerability
    2Low Vulnerability
    3Medium Vulnerability
    4High Vulnerability
    5Very High Vulnerability
    Count
    Number of cells (Source: Esri)
    Range of values
    Minimum:21366747
    Maximum:57871306

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Steven H. Douglas
  2. Who also contributed to the data set?
    U.S. Geological Survey and University of South Florida St. Petersburg
  3. To whom should users address questions about the data?
    Cherokee Nation Technologies contracted to the U.S. Geological Survey
    Attn: Steven Douglas
    600 4th St S
    St. Petersburg, FL

    727-502-8134 (voice)
    sdouglas@usgs.gov

Why was the data set created?

This dataset was generated from the DRASTIC model to test the model's ability to indicate intrinsic groundwater vulnerability in the Southwest Florida Water Management District (SWFWMD).

How was the data set created?

  1. From what previous works were the data drawn?
    SIM3182 (source 1 of 6)
    U.S. Geological Survey, 20111117, Potentiometric Surface of the Upper Floridan Aquifer in Florida and in Parts of Georgia, South Carolina, and Alabama, May – June 2010: U.S. Geological Survey, Orlando, FL.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    Potentiometric surface was used as the depth to groundwater variable in the DRASTIC model equation.
    SWFWMD (source 2 of 6)
    Mapping and GIS Section, Southwest Florida Water Management District, 2002, Aquifer Recharge/Discharge data from USGS 2002 Model: Southwest Florida Water Management District, 2379 Broad Street, Brooksville, FL 34604-6899.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    Aquifer recharge/discharge was used as the recharge variable in the DRASTIC model equation.
    USGS HA-730 (source 3 of 6)
    U.S. Geological Survey, 200310, Principal Aquifers of the 48 Conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands: U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    The aquifer rock type field was used as the aquifer media variable in the DRASTIC model equation. For additional information, please see the metadata for the data file available here: https://water.usgs.gov/GIS/metadata/usgswrd/XML/aquifers_us.xml.
    SSURGO (source 4 of 6)
    U.S. Department of Agriculture, Natural Resources Conservation Service, 2015, USDA-NRCS Soil Survey Geographic (SSURGO 2.2): texdesc and ksat_r: USDA/NRCS - National Geospatial Center of Excellence, Fort Worth, TX.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    Texdesc was used as the soil media variable and ksat_r as the saturated hydraulic conductivity variable in the DRASTIC model equation.
    FLIDAR_MOSAIC_M (source 5 of 6)
    Florida Geographic Data Library, 201301, Florida Digital Elevation Model (DEM) Mosaic - 5-Meter Cell Size - Elevation Units Meters (FGDC): University of Florida GeoPlan Center, Gainesville, FL.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    The 5-meter DEM was used as the topography variable in the DRASTIC model equation.
    fdepgeo (source 6 of 6)
    Florida Geographic Data Library, 2001, Geology (Environmental): Florida Geographic Data Library, Gainesville, FL.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution:
    The CATEGORY field was used as the Impact of the Vadose Zone variable in the DRASTIC model equation
  2. How were the data generated, processed, and modified?
    Date: 2015 (process 1 of 6)
    Tabular and map Soil Survey Geographic Database SSURGO data for Florida were downloaded through the U.S. Department of Agriculture (USDA) Geospatial Data Gateway. Descriptions for the SSURGO classes are available at the Soil Survey website http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_054253. SSURGO metadata is available at: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/home/?cid=nrcs142p2_053631. The polygon SSURGO shapefiles were joined to the tabular files within the file geodatabase. The first join to be made uses the “mukey” field as the common identifier to join the cokey field from the “component” table. The second join to be made uses the cokey field as the common identifier to join the ksat_r (Saturated Hydraulic Conductivity) field from the “CHorizon” table. Finally, the chtexturegrp join was made using the chorizon field as the common identifier to join the texdesc (Texture) field. The texture and rock type variables are expressed as descriptive text. They were reclassified as numerical values based on the methods described by Aller and others (1987). The final polygon shapefile was converted to a 10-meter raster GeoTiffs using the Polygon to Raster tool. Person who carried out this activity:
    Steven H. Douglas
    Cherokee Nation Technologies contracted to the U.S. Geological Survey
    600 4th St S
    St Petersburg, FL

    727-502-8134 (voice)
    sdouglas@usgs.gov
    Date: 2015 (process 2 of 6)
    SWFWMD Recharge converted to inches per year based on Aller and others (1987).
    Date: 2015 (process 3 of 6)
    Aquifer media reclassified based on Aller and others (1987).
    Date: 2015 (process 4 of 6)
    Topography converted to percent slope using the Slope tool in the Surface toolbox in ArcGIS based on Aller and others (1987).
    Date: 2015 (process 5 of 6)
    Impact of the vadose zone reclassified based on Aller and others (1987).
    Date: 13-Oct-2020 (process 6 of 6)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Aller, L., Bennet, T., Lehr, J. H., Petty, R., and Hackett, G., 198705, DRASTIC: A standardized system to evaluate groundwater pollution potential using hydrogeologic settings: National Water Well Association, U.S. Environmental Protection Agency, Dublin, OH.

    Online Links:

    Douglas, S., Dixon, B., and Griffin, D., Unknown, Assessing intrinsic and specific vulnerability models ability to indicate groundwater vulnerability to groups of similar pesticides: a comparative study: Physical Geography, Philadelphia, PA.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    No formal attribute accuracy tests were conducted.
  2. How accurate are the geographic locations?
    No formal horizontal positional accuracy tests were conducted.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the data-set has either not been conducted, or is not applicable.
  4. Where are the gaps in the data? What is missing?
    Data-set is considered complete for the information presented, as described in the abstract.
  5. How consistent are the relationships among the observations, including topology?
    Raster values were checked for consistency with expected values.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    Cherokee Nation Technologies contracted to the U.S. Geological Survey
    Attn: Steven Douglas
    600 4th St S
    St Petersburg, FL

    727-502-8134 (voice)
    sdouglas@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The data have been approved for release and publication by the U.S. Geological Survey (USGS). Although the data have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, the data are released on the condition that neither the USGS nor the U.S. Government may be held liable for any damages resulting from authorized or unauthorized use. Although the data have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS shall not be held liable for improper or incorrect use of the data described and/or contained herein. Users of the data are advised to read all metadata and associated documentation thoroughly to understand appropriate use and data limitations.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Metadata author:
Cherokee Nation Technologies contracted to the U.S. Geological Survey
Attn: Steven H. Douglas
600 4th St S
St. Petersburg, FL

727-502-8134 (voice)
sdouglas@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/DRASTIC_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:47 2021