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Data Analysis
The FIELDS Tools provide a range of data analysis options. These options are broadly defined as sample design, database query, and data and decision analysis.
Sample Design
Sample design capabilities include the creation of statistically-based
sample designs (random, stratified random, systematic grid, and unaligned
grid) and the ability to upload these designs to a GPS unit in order to
navigate to sample locations. The parameters used to create the sample
design (e.g., number of sample locations, sample area, false negative
values) are exported as a table that can be included in a report.
Database Query
The FIELDS query tool can be used to query all results; the maximum result
in 3-dimensions, the maximum result in 2-dimensions, and results by interval
(e.g., 0-6 inches, 6-12 inches) either using a depth-weighted average
algorithm or the maximum results per interval. The input data can be from
a FIELDS-defined data table or imported from databases such as STORET,
EQuIS, or NOAA’s Query Manager database. If the input data has field
names or types that do not match the FIELDS-defined data table format,
an interactive GUI allows users to match their field names with the FIELDS-required
names.
Data and Decision Analysis
The resulting queried data values can be used in the Human Health Risk
or Ecological Risk Assessment modules. Each module meets U.S. EPA guidelines
(RAGS and ERAGS) for risk assessment. In addition, the queried data can
be contoured (interpolated) to create estimates at unsampled locations
using Dr. Dave Watson’s Natural Neighbor algorithm or ArcView’s
Inverse Distance Weighting (IDW) algorithm. The FIELDS Tools also includes
a cross validation routine that generates root mean square errors (RMSE)
of estimation for permutations of IDW parameters number of neighbors and
power.
The contoured values can be used to estimate the mass of contaminant (e.g., pounds of PCB) and the volume of contaminated material (e.g., sediment > 10 ppm) using the Mass/Volume module. Finally, the FIELDS Tools includes a Remediation module that allows users to determine areas to remediate in order to meet a clean-up goal by remediation unit (called block-based remediation) or for the entire site (i.e., to meet an average concentration value for an entire area).