HYDROGEOCHEMICAL CHARACTERISTICS OF THE Sv. IVAN SPRING IN ISTRIA, CROATIA

In addition to geological, hydrological and hydrogeological invcstigations and $roundwater tracing, detailed surveyin of the groundwater quality IS becoming particular1 important for environmental impact monitoring on karst aquifers. &roundwater qualitydata contain NO types of information, i.e. the natural chemistry of water and its caused by anthropognicimpacts. The method of results presentation a . well as the importance of water quality surveying, particularly with respect to the indicators showing it. natural chemistry, are shown here exemplified by the Sv. Ivan spring in Istria, Croatia. Natural chemistry of the groundwater is a consequence of hydrogeochemical facies, and it is u.ed here for interpretation of s ring generating conditions and the origin of groundwater. Results optained so far confirm that the extent of recharge area of the spring change in dependence of thc hydrological conditions. H dro eochemical charaderistin of the spring are presented grapiical& in the form of correlation diagrams showing major groundwater parameters, saturation conditions and trends of particular parameters as a function of time.