Probabilistic evaluation of the extent of the unconfined aquifer

The research mainly aimed to present a novel application of the technique based on the Dempster-Shafer theory for the determination of the aquifer extent in a nonparametric (probabilistic) scale. Data analyses were carried out in the Geographic Information System. All the data were imported to the IDRISI 32 release 2. The Dempster-Shafer probability theory supported by the module BELIEF of IDRISI software was applied to the algebra of pixel maps. The research area covers 1300 km^2 in the eastern part of the Pomeranian Lakeland. The geology of this area is dominated by Pleistocene postglacial sediments. The study area comprises unconfined aquifers and four main confined aquifers. Only the unconfined aquifers were taken into account in the study described in these paper. The resulting image showed a map of the aquifers’ extents in a probabilistic scale, i.e., in a range between 0 (lack of the aquifer confirmed by field research) and 1 (occurrence of the aquifer, also proved by research).