Zmienność chemizmu wód podziemnych na obszarze Łodzi 327–336.

Abstract

CHEMICAL VARIABILITY OF GROUNDWATER IN THE AREA OF THE ŁÓDŹ CITY (CENTRAL POLAND) Summary This papers presents a picture of chemical variability of groundwaters in a region of high anthropogenic pollution, around the city of £ódŸ. The research as conducted in three groups of wells, all representing aquifres of potable waters within the Łódźhydrogeological basin. Two groups of wells chosen within the city area and one outside it, in a rural area. Research showed that the Łódźhydrogeological basin were presents the inversion type, regarding mineralization and chemical composition of water. Within Cainozoic rocks, inversion is caused by anthropopression, but in deeper aquifers geogenic processes play a domiant role. The same pattern of conditions varies also horizontally in each aquifer. Ca, Mg, Na and Cl ions are of greater importance in the group of indicators of hydrochemical variability of groundwaters. These elements have connection with pollution processes of groundwaters, visiblein changes of hardness and salinity. Hydrochemical changes are also indicated by NO2 and NH4.Isotopic compositions of waters from the Cretaceous aquifers, which were identified locale, clearly show age inversion.Water from theUpper Cretaceous aquifer areolder by one order of magnitude than waters from Lower Cretaceous aquifer. Identified hydrochemicalvariability of waters within Upper Cretaceous aquifer may indicate its hydrodynamicalzonality.