Applications of HRR:
- Identify and characterize vadose and saturated zones
- Map ground water infiltration vertically and laterally
- Quantify infiltration rates
- Identify possible preferential ground water pathways in fracture flow aquifers
- Identify and characterize major subsurface geologic structures
- Identify lithologic contacts including depth to shallow bedrock
- Characterize lithologies
- Quantify subflow
- Identify and characterize shallow subsurface paleochannels
- Locate and map contaminant plume migration
- Map and characterize contiguous areas of landfill deposits
Technique Description:
Electrical resistivity field data are collected using a resistivity instrument (data receiving
and recording instrument), electrodes (sensors), an electrical energy source (transmitter), and
some sort of cable or wire interconnection between them.
A typical survey consists of some variation of a four-electrode array with two electrodes forming a transmitting
pair or dipole whereby electrical current is injected into the earth and two electrodes forming a receiving pair or
dipole measures the voltage difference due to the impressed current.
The electrodes are commonly deployed in a collinear (one-dimensional) or two-dimensional array for
two-dimensional or three-dimensional investigations, respectively. Survey line locations are determined
by the target objective and may range from a single profile to
complete three-dimensional coverage. Spacings are dictated by target size and depth of burial. For
conventional shallow investigations, the distance between the two active electrodes typically varies
between 5 and 400 feet.
hydroGEOPHYSICS, uses in-house reduction software to process the resistivity data. The theoretical basis,
algorithims, and field procedures for High Resolution Resistivity (HRR)were developed over the last 20 years
by our President, Dr. James
Fink. Our unique software allows accurate incorporation of ground surface topographic effects, which provides
a realistic cross-sectional presentation.
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