Abstract:
Understanding trends in ground water contaminant concentrations
is complicated by the fact that ground water quality
presents complex three-dimensional trends over multiple
spatial scales. To address this issue we have developed
a method to jointly display three-dimensional ground
water quality and topographic data. This approach allows
the user to: 1) identify local areas of elevated contaminant
concentrations, 2) identify particular topographic features
(river valleys, plateaus, etc) associated with elevated concentrations,
3) assess differences among aquifers and well
use types, and 4) identify associations among different constituents.
The approach used here links geospatially referenced
concentration data with elevation data contained in
Digital Terrain Elevation Data (DTED) files within an
easy-to-use MATLAB-based visualization system. The method
was applied to visualize information on nitrate and arsenic
occurrence in a national ground water quality database.
The method shows that high arsenic is associated with the
transition from plains to piedmont in New Jersey. Nitrate
in Iowa is shown to be associated with shallow wells in the
southeastern portion of the state. The approach developed
here is compatible with any Microsoft Excel Spreadsheet
database which follows specific format conventions.
