2.3 Location of Karst Water Channels

In 1982, the Swedish university of Lund (Universitets Naturgeografiska Institution of Lund) implemented a comparative study for the location of karst water channels on Gotland Island. For that purpose, three geophysical techniques (Slingram, VLF, ground radar) had been used parallel to the dowsing technique and analyzed with respect to their respective prospecting power for specific tasks [21].

Within two areas of the Gotland Island, 6 test courses and 2 test terrains were selected for the experiments. It was well-known that ground water did not occur in extended strata, but flows through fractures and openings in the limestone (karst). Sometimes, very pronounced karst water channels as well as subterranean rivers and galleries occur.

The first test area near Tingstäde was a fenced terrain of 80 x 20 m, protected against observation from outside. Inside, a 22 m long test course and a test field of 50 x 15 m were pegged out. The organizers of the experiment had good reasons to assume that below the area an underground river was present, in a depth of no more than 20 m, but its exact location was not known prior to the experiments.

The second test area included 5 test courses, each of 50 m length, and a test field of dimensions 40 x 40 m; in all cases, the position of the approximately 20 m deep underground river Lummelunda had to be located. The channels and galleries formed by the river were partly 5 m wide and high; this has been reported by divers who had already investigated the river at some points. Again, the exact positions of the river in the test area were unknown before the experiments. The organizers all agreed in their opinion that the surface at and around the test fields offered no signs or indications which could be used for the location of the subterranean channels.

During several test days, 33 test persons were appointed as dowsers. The larger number had dowsing experience before and half of them claimed to have located wells quite frequently. In all 8 experiments, the task consisted in localizing the position of the supposed gallery; on both test fields, the direction had also to be indicated. Each tested person was individually guided to the test area without being watched by others. Those who had already carried out the experiments waited separately from the others who had still to perform the tests. None of the test persons knew the terrain; 30 of the dowsers had never been on the island before. During the experiments, neither the dowsers nor the supervising crew knew the exact position of the investigated channels (double-blind procedure).

After the dowsing tests had come to an end, the three previously mentioned geophysical measuring procedures were carried out, as well as some inspection of the underground river in order to geometrically pinpoint the precise locations of the karst channels. In 7 of 8 cases these procedures were sufficiently accurate. A more detailed discussion of the quite problematic and more or less appropriate technical procedures is reported in other documents [21].

Results of the Swedish Study

Altogether, the results obtained from the dowsing experiments are comparable with the Munich tests carried out in the open field. The majority of the test persons produced dowsing reactions along the entire course (i.e. not just at the places where they actually crossed the channels), but about a third of the dowsers had reliable and statistically significant reactions. A total analysis of this data led the authors to the conclusion that dowsers are able to sense karst water channels with such a high accuracy that the hypothesis based on pure chance success could not be maintained.

The outcome will be discussed for the case of tests carried out on the 50 x 15 m field. 29 dowsers participated and tried to locate both position and direction of a supposed subterranean channel. When the resulting lines were plotted on a plan, they cover almost the entire field; there was, however, a well pronounced accumulation: more than half of all indicated lines lie on a small tract. The later measurements of the supposed channel by means of ground radar turned out to correspond extremely well with this tract.

When all the directions indicated by the dowsers are plotted in an angular diagram, a most surprising result is revealed: it turns out that the given directions mostly indicate two perpendicular directions (but not the main cardinal points). More than 90% of the lines belong to two groups which form an angle of 90 +/- 10 degrees. This is normally the angle between vertical fractures in horizontally situated limestone; geophysical investigations have corroborated this fact also for the karst underground on Gotland.

Fig. 13. Results of 29 test persons (dowsers), obtained at a test area situated over karst channels on Gotland Island. Above: plot of all 152 directions and locations indicated by the dowsers and attributed to subterranean channels. Beneath: subsequent result of radar measurement ( - - - direction of the main channel).

Fig. 14. Results of 29 test persons (dowsers), obtained at a test area situated over karst channels on Gotland Fig. 14. Angular diagram showing the 152 directions (data from above) of the supposed water channels as indicated by the dowsers.

Fig. 15. Result of one of the tests carried out along a course which crosses a subterranean karst water channel. The black square shows the location of the sought channel as determined later by measuring techniques. Above: strength of the earth-magnetic field. Beneath: reaction points of the 20 test persons who claimed to have detected strong water carrying channels.

Among the 6 location experiments of channels along test courses, 5 cases turned out to be significant, whereby 2 cases were highly significant. Along the course with 22 m length, 11 of the 20 participating dowsers produced hits; 11 of the total of 33 reactions occurred within the 2 m wide target interval at the mark of 13 +/- 1 m (see sketch). The probability that this result can be attained by accident is less than 1 : 40.

The relative simplicity of the experiments and the observed accuracy of aim of the dowsers suggest that such experiments should also be incorporated into future dowsing tests. The choice of the area will apparently be decisive: karst underground with shallow channels seems to be particularly appropriate for such tests.