Analiza współzależności stężenia jonów w wodach podziemnych i ciśnienia piezometrycznego w punktach monitoringowych nr 6, 226 i 581 sieci obserwacyjno-badawczej PIG-PIB w wieloleciu 1991–2014

The aim of the study was to describe how the potentiometric surface fluctuations are able to influence on the concentrations of ions in groundwater. The research based on the data provided by the groundwater monitoring network of the Polish Geological Institute – National Research Institute (PGI-NRI) from the Warta catchment in the period of 24 years of record (1991–2014). In the first stage of analysis the measured concentrations of ions: Cl–, Mg2+, Mn2+, Ca2+, Na+, SO4 2–, K+, HCO3 – were examined in conjunction with the groundwater level fluctuations in 29 monitoring points (in case of confined aquifers “groundwater level” was regarded as the potentiometric surface measured in the hydrogeological borehole). There were found statistically significant correlations between some of the concentrations of analysed ions and the fluctuations of groundwater level. Ions: Mg2+ in the point nr 6 and 226, Cl– and Na+ in the point nr 581 were subjected to further testing because their concentrations showed the strongest linear correlation with the potentiometric surface. In the second stage of study, the classical least-squares regression method was applied to build the linear models for these dependencies. The obtained results show that the fluctuations of potentiometric surface were able to explain from 30 to 56% of the variation of ion concentration.