The water table can act as a seismic reflector, so a shallow seismic reflection survey can be used, but there are a number of limitations to the method - it  needs the water table to lie within a relatively homogeneous stratigraphy, otherwise lithological reflections will make interpretation difficult. Seismic reflection surveys are expensive - in equipment, in data acquisition and in interpretation, and imaging with seismic reflection at depths of < 30 metres gets progressively harder. So it can be done, but whether it's economically worth doing is questionable. I think I would sum up as saying that there isn't a single ideal non-invasive method to determine depth to the water table, all (?) geophysical methods require interpretation within a geological context.  It's fairly rare for there not to be some data from a borehole or well in a similar geological and topographic context, even if not in the same location, and it's probably more valuable to make a real effort to find pre-existing data or survey existing water points than to conduct speculative geophysical surveys without geological context. If it truly is an 'unexplored' area, at some early stage it will be necessary to drill an exploration borehole to prove the lithological sequence, aquifer properties and water quality At which point you have the opportunity to design and calibrate an appropriate geophysical survey.

Published by

The water table can act as a seismic reflector, so a shallow seismic reflection survey can be used, but there are a number of limitations to the method - it  needs the water table to lie within a relatively homogeneous stratigraphy, otherwise lithological reflections will make interpretation difficult. Seismic reflection surveys are expensive - in equipment, in data acquisition and in interpretation, and imaging with seismic reflection at depths of < 30 metres gets progressively harder. So it can be done, but whether it's economically worth doing is questionable.

I think I would sum up as saying that there isn't a single ideal non-invasive method to determine depth to the water table, all (?) geophysical methods require interpretation within a geological context.  It's fairly rare for there not to be some data from a borehole or well in a similar geological and topographic context, even if not in the same location, and it's probably more valuable to make a real effort to find pre-existing data or survey existing water points than to conduct speculative geophysical surveys without geological context. If it truly is an 'unexplored' area, at some early stage it will be necessary to drill an exploration borehole to prove the lithological sequence, aquifer properties and water quality At which point you have the opportunity to design and calibrate an appropriate geophysical survey.