Surface Geophysical Methods in Hydrologic Studies

General Method Specifc method Use in study
(and depth of exploration)
Type of interpretation
(and status)
Limitations Advantages
ELECTRICAL DC Resistivity Map complex plumes, complex stratigraphy Quantitative (production) Slow; electrical, cultural interference; need larger areas for deep work Detailed results
  Terrain Conductivity Map simple plumes and stratigraphy      
  EM 31 (Shallow) Qualitative (production)
quantitative (research)
Electrical, cultural interference Fast; simple to use
  EM 34-3 (Moderate) Qualitative (production)
quantitative (research)
Electrical, cultural interference Fast; simple to use
  Time-domain EM 37W Map plumes and stratigraphy Qualitative (research) Complex to use Small surface area for deep penetration
  Terrain resistivity Map simple plumes and stratigraphy      
  Very low frequency (VLF) EM 16R (Moderate) Qualitative (production)
quantitative (research)
Electical, cultural interference Fast; simple to use
  Ground Penetrating Radar Map water table and stratigraphy (shallow) Qualitative (research) Complex to use Very fast
  Complex resistivity Map non-conductive plumes (shallow) Qualitative (research) Complex to use; slow; must have clay present Can map non-conductive contaminant
SEISMIC Land refraction Map depth to water, depth to rock (shallow or deep) Quantitative (production) Cultural noise interference; may need explosives; need larger areas for deep work Detailed results
  Land reflection Depth to rock (moderate to deep) Quantitative (research) Cultural noise interference; may need explosives Small areas for deep work
  Marine reflection (single channel) Detailed stratigraphy, depth to rock (shallow to moderate) Quantitative (research)
qualitative (research)
Need water Very fast

A good reference describing the theory and practice is:
Ward, S. H. (editor), Geotechnical and Environmental Geophysics, Investigations in Geophysics series, no. 5, v. I-III: Tulsa, Oklahoma, Society of Exploration Geophysicists, 1032 p., 1990.

 
 
Last updated on August 6, 1998 by William P. Clement

© William P. Clement 2000