ABSTRACT: The aim of this study is to evaluate the isotopic and chemical composition of the water resources heated inAntalya Travertine Plateau by using cluster and factor analysis.. Major ions (Ca , Mg ., Na , K » Cf» SO4, HCOs+CÖ3~)„ electrical conductivity (EC), dissolved oxygen (DO),,, CO2, total dissolved solid (TDS), partial CO2 pressure (PCO2), saturation index (SI) and environmental isotope values of springs and wells have been used to estimate the similarities and disparities between the water sources.,The use of muitivariate statistical analyses., which allows evaluation of a large amount of parameters,, is veryhelpful in Hydrogeologie analysis of complex groundwater systems. DaUon and Upckurch (1978), Williams(1982), Steinhorst and Williams (1985), Usunoffand Guzman (1989), Reeve et.al (1996),, Helena et.al. (2000),and the others have emphasized the potential use of the muitivariate analysis techniques for the hydrochemicaiinterpretations of the groundwater systems.The study area occupies 630 km . The geological structure and the map of the sampling locations are illustrated on Figure 2., The Antalya. Travertine Plateau has a. stepwise morphology. In the upper step, called, as Upper Plateau, there are many springs discharging from the Mesozoic limestone and the travertine,. The most importantof these springs are the outlets of the Kırkgöz Spring zone discharging from Mesozoic karstic limestone (KGI,KGM, KGO, KGK, KGP). The average discharge rate of these outlets is 15 m/s. The significant springs discharging from the Lower Plateau are Düdenbaşı spring (DUD),, Kemerağzı spring (KMÄ), Mağara spring(MGR), Ârapsuyu spring (ÀRP), and Duraiiler-Oku! spring (DUO). The average discharge rate of the Düdenbaşıspring is 17 m/s, whereas the averages of the other springs are between 0.5-2.5 m /s. Another important springis Hurma spring (HRM) discharging from Antalya Nappes. The other sampling points in the study area are Bıyıklı(BIY) and Yağca (YGC) swallow-holes at the Upper Plateau, Varsak (VAR) deline, `Kapuz river (KPN), Meydanwells (ASO) and the Duraliler pumping station (DUP), at the Lower Plateau. The chemical,, physical and isotopedata values of these sampling points are given in Table !.. The cluster and factor analysis of the environmentalisotopic and hydrochemical data provides the classification of the water sources of the Antalya TravertinePlateau in terms of the ionic composition, the saturation levels and the transit time of the waters.The classification of the standardized isotopic and hydrochemical parameters by cluster analysis is given onFigure 3, while the classification of the water sources with these parameters is given on Figure 4. The parameters are grouped in classes representing i) the major ion composition (TDSr EC, Cd - HCOs +CO£~), ii) thedegree of the saturation with respect to carbonate minerals (SI, pH, DO), and Hi) the source and the age of thewater (isotopes, Cl-3 Temp).. Clustering of the water sources results two distinct classes: Upper Plateau groundwaters and Düdenbaşı springs is located in the same class, while all the other Lower Plateau springs are in thesecond class.. The dotinesfed by Kırkgözler Spring and the Kapuzbaşı surface water are out of these classes.Principal factor analysis provided three principal factors for the processes controlling` the ionic and isotopiccomposition. These are the total dissolved solids, the degree of the saturation with respect to carbonate mineralsand the isotopic composition.. These three factors explain the 95% of the total variance of the parameters.. Thecorrelations of the parameters with the factors are given on Figure 5. The classification with respect to factorsindicated that the Kırgözler and Düdenbaşı springs are characterized by high amount of carbonates,, and highdegree of the carbonate saturation,, and higher recharge areas. On the contrary, the Lower Plateau springs arecharacterized by low amount of carbonates, low saturation levels and lower recharge areas.. The principal factor analysis also revealed that the outlets of the Kırkgöz springs have different recharge areas and different transit times