Abstract
The Olkusz area is characterized by very complicated hydrogeological conditions. The Quaternary, Jurassic, Triassic and Palaeozic groundwater horizons represent porous or fracture-karstic types. The groundwater horizons are in permanent hydraulic contact. Natural hydrogeological conditions were highly disturbed, mostly by intensive mine drainage, which reached peak discharge of 350 m3/min and resulted in the formation of depression cone covering several hundreds of square kilometers. The closure of zinc and lead ore mining activity in the Olkusz region, scheduled to be completed before 2012, will give rise to both qualitative and quantitative, regional changes in the aquatic environment. Hence, a new concept is necessary of water supply in the area. The paper presents hydrogeological prognoses which consider the changes in aquatic environment of the Olkusz area during mine closure and the presumed water supply. The prognoses were based upon modelling of filtration area extending over 937 km2. The model considers two groundwater horizons: upper, which includes Quaternary-Jurassic strata and lower, which embraces Quaternary-Triassic-Devonian sediments, both separated by low-permeable, Rhoethian-Keuper beds.
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