ABSTRACT
"Evaluation of extend of aquifer by data analysis in Geographic Information System on the example of resarch area from Pomeranian Lakeland"

The research primarily aimed to develop a technique of analyzing data for the determination of the aquifers extent. The extent of the aquifers was shown in a nonparametric (probabilistic) scale.

         Data analyses were carried out in the Geographic Information System. Several raster and vector GIS programs, such as: MGE Basic Nucleus^® (decoding data project), Geomedia^® Professional (SQL queries and data export), ArcView^® (data export and import) and Mapinfo^® were applied in the research.

All the data were imported to the main program called IDRISI 32 release 2^®. The program supported a special procedure for analyzing fuzzy data and provided other useful tools.

         The main source data were taken from a digital project of the Hydrogeological Map of Poland in a scale 1:50 000 (HMoP). All the sheets of the HMoP were prepared for data analysis in the GIS. Also the information obtained from the analog hydrographic map was applied. In the data analyses of the confined aquifer, the Digital Elevation Model of Terrain (taken free from the INTERNET (GLOBE^®)) was performed.

         The research area covers 1300 km² from the Tucholskie Forest (the east part of the Pomeranian Lakeland). The geology of this area is composed of the Quaternary postglacial sediments mainly. The study area comprises one unconfined aquifer and four main confined aquifers. The extent of each aquifer was established separately.

As a result, five images representing aquifers were made. All the images showed the maps of the aquifers’ extents in a probabilistic scale i.e. in a range between 0 (the lack of the aquifer) and 1 (confirms the occurrence of the aquifer). The Dempster-Shafer probability theory supported by the module BELIEF of IDRISI software was applied to the algebra of pixel maps.