A GPR SURVEY FOR WATER EXPLORATION IN A CRYSTALLINE ROCK TERRAIN

Résumé

The vast majority of mineral water occurrences in Brazil are associated to
fractures zones in crystalline rocks. Underground water exploration is usually based on
geological studies (photo-interpretation) combined with geophysical surveys, mainly
electrical methods and VLF.
In this paper we demonstrate the use of GPR method in the exploration of underground
water in crystalline terrain. An example of data collected at one known spring in the district
of Petrópolis is given. Petrópolis is a major producer in the Rio de Janeiro State. The
saturated region is clearly outlined in the GPR section as a zone of attenuation and
inversion of the wavelet phase polarity.