Ocena zmian stężenia chlorków w solankach Uzdrowiska Goczałkowice-Zdrój przy zastosowaniu metod statystycznych

The article presents the assessment of the groundwater quality trend on the example of chlorides in the region of Goczałkowice Zdrój health resort. The data from the years 1977–2014 from two boreholes: GN-1, GN-2 were analysed. The trend assessment was made using the linear model, the fixed effect model and the robust statistic. The results of these methods indicate a downward trend of chlorides concentration.