ZMIANY SKŁADU CHEMICZNEGO WÓD ŹRÓDEŁ W TATRACH POLSKICH W OSTATNIM SZEŚĆDZIESIĘCIOLECIU

Abstract

CHANGES IN THE CHEMICAL COMPOSITION OF SPRING WATER IN THE POLISH TATRA MTS. OVER THE LAST SIXTY YEARSAbstract. Comparison of the present chemical composition of spring water with the archival research revealed significant changes in the selected main ion concentrations over the last 60 years. The interpretation of changes in the chemical composition of water was based on the concentration of bicarbonates, calcium and magnesium of the same 105 springs in three periods (1952–1962, 1970–1980 and 2007–2010). Due to the geological structure, the changes in the concentration were assessed within the groups of springs draining crystalline rocks (n = 54) and sedimentary rocks (n = 51). The course of the observed changes in the concentration of the selected ions is different in spring water draining the crystalline core than in springs draining sedimentary series. The springs located in the crystalline part of the Tatra had the highest concentrations of HCO3-, Ca2+ and Mg2+ in the 1970s of the 20th century and their maximum concentration was even twice higher in this period than in the 1950s–1960s of the 20th century. The analysis of the most frequently occurring concentrations of HCO3-, Ca2+ and Mg2+ in water draining the crystalline core indicates the similarity of the chemical composition of water in 1952–1962 and present (2007–2010). A gradual increase in the concentration ofHCO3- and Ca2+ particularly, and to a lesser extent Mg2+, from the 50s of the 20th century to present is a characteristic feature of spring water draining sedimentary series.