WPŁYW STREFY AERACJI W WAPIENIACH JURY GÓRNEJ NA SKŁAD CHEMICZNY WÓD PODZIEMNYCH W OJCOWSKIM PARKU NARODOWYM

Abstract

INFLUENCE OF THE UNSATURATED ZONE IN UPPER JURASSIC LIMESTONES ON THE CHEMISTRY OF GROUNDWATER (OJCÓW NATIONAL PARK, SOUTHERN POLAND)

Abstract. On the territory of Ojców National Park, situated between two urban-industrial agglomerations: Silesia and Cracow, surface sediments consist mainly of the Upper Jurassic, jointed, karstified limestones. The main factors harmfully affecting the natural environment are atmospheric pollutants spread by winds that decrease the mean precipitation pH value to 4.7–4.8. This paper attempts to estimate the influence that the unsaturated zone in the Upper Jurassic limestones has to the chemical composition of groundwater. Macro- and microelement loads determined in: precipitation, the aeration and saturation zones and in the Prądnik river waters were compared. As a result of acid rain buffering processes the calcium and sulphate loads in the zone of aeration significantly increased. A considerable increase in the chloride and sodium ion loads also occurred. In the saturation zone as well as in the Prądnik river, the sulphate load is much smaller, while the loads of the remaining elements are similar to the loads in the unsaturated zone, where the analysed metals (Fe, Mn, Zn) were stopped. Their loads increased slightly in the zone of saturation and in the Prądnik river water. Waters with an increased sulphate concentration migrate slowly towards the zone of saturation and results in a threat to the groundwater quality in the Upper Jurassic limestones of Ojców National Park.