A new approach to a hydrochemical study of groundwater flow

A statistical approach based on a multivariate correlation Of various hydrochemical parameters has been developed for the interpretation of groundwater how lines of the Vasilikon basin in the southern part of the central area of Euboea island in Greece. Water samples, mainly from wells but also from boreholes, were collected and analysed for 44 hydrochemical parameters, from which the conductivity, dissolved O-2, Ca, Mg, chloride, acid-consuming capacity, base-consuming capacity, Si, Fe and As were selected for the evaluation. After normalization of each parameter by z-transformation - to equalize the influence of parameters with small and large variations - a classification of the sampling stations was obtained by cluster analysis. By the use of the same z-transformed data the degree of similarity of element-concentration (z-transformed) profiles between the central sampling points and the surrounding sampling points was investigated. The resulting radially distributed correlation vectors were reduced to the main axis of an ellipse, so that flow lines or trend of groundwater movements became visible. The results of this method were also compared with hydrogeological observations of the Vasilikon basin.