Environmental Scientist M.Sc. 2010 Water chemistry analyses in the Baradla and Béke Caves using Multivariate Exploratory Techniques Edit Borbás – ELTE Environmental Scientist M.Sc. 2010 25-26.03.2011 ISZA 2011, Győr

Outline Introduction Aims of the study Water sampling Location Geology and Hydrology Research History Aims of the study Water sampling Hydrochemical analysis Multivariate Exploratory Techniques Summary Acknowledgements

Location of the caves studied Located in Northeast Hungary, Gömör-Torna-Karst, in the Aggtelek National Park World Cultural and Natural Heritage, UNESCO (1995) Baradla Cave

Geology and hydrology of the caves Baradla Cave Baradla-Domica Cave system: 27 km, Béke cave:7 km Developed in Triassic limestone partly overlaid by Pannon sediment and partly uncovered karst filling-erosion cycle Creeks in the caves are temporary active (sink-holes on the surface, infiltration) Béke Cave Baradla cave: Short Lower Cave – 1km (Jósva-Táró spring) Long Lower Cave – 150m (Jósva-Medence spring) The evolution of the Baradla Cave (Berényi et al., 2006) showing how the cave filled up with sediment and how the sediment was transported from the cave by the floods of the creeks Béke Cave

Research history The study of the cave sediment began in 2002 (Niphargus Cave Research Group) the main mineral component of the sediment is quartz Radon measurements in 2003 water was observed in the sediment Observation wells settled between 2004 and 2008: Baradla Cave: Olympos well (6.45 m), Styx well (4.75 m) Béke Cave at the 86 reference mapping point: Béke well (4.7m) 2006: water level monitoring in the Olympos well close connection between the weather conditions and the water level in the observation well Styx well closed and open The effect of spring snow break on the water level of the Olympos well in 2006 (Berényi et al., 2006) (the straight line shows the level of the terrain, mBf = meters above Baltic Sea level)

Aims of the study To sample the water and conduct hydrochemical analyses on the samples retrieved from the caves, and the springs on the surface To determine the connection between the water in the observation wells and the other sampling locations of the caves’ system To observe, if and how the chemical contents of the creeks and sediment waters changed during the snowbreak in February 2010 To compare the measurements’ results to the archive data (1980-1983 & 2003-2005)

Sampling locations on the surface Samples from the: wells settled in the sediment creeks in the caves springs on the surface Baradla Cave Béke Cave 2km Sampling locations on the surface EOV-X EOV-Y Táró spring 349980 760520 Medence spring 349990 Komlós spring 349694 760763 „Ház-sarki” spring 349772 760813 Sampling points in the caves: Baradla Cave: Styx creek, Styx well, Olympos well, Olympos pit Béke Cave: Komlós creek, Béke well Baradla Cave Béke Cave

Medence spring Táró spring Styx creek Olympos well Komlós spring „Ház-sarki” spring Olympos pit Baradla Cave Béke Cave Styx well Komlós creek Béke well

Material and methods Own hydrochemical analyses November 2009 – April 2010 10 sampling locations, 94 samples (1316 data) Examined chemical parameters (according to the Hungarian standards): Ca2+, Mg2+, HCO3-, Cl- (mg/l)(Titrimetric Method) Na+, K+ (mg/l)(Flame Photometric Method ) NH4+, NO3-, NO2-, SO42- , PO43- (mg/l) (Spectrometric Method) Temperature (0C) Electrical conductivity (mS/cm), pH

Materials and methods Water sampling Hydrochemical analyses Results Chemical composition of the waters (Stiff diagram, Piper diagram) Cluster analysis Discriminant analysis Box and Whisker diagrams Multivariate Exploratory Techniques

Effect of the snowbreak on the chemical composition of the waters (Stiff Diagrams): on the water level in the observation wells:   Olympos well Styx well Béke well Date Level from the top(cm) 01.31.2010 202 281.5 83 02.13.2010 239.5 252 85.5 02.20.2010 251 230 n.a. 02.27.2010 65.5 138 98 03.13.2010 65 155 77 03.27.2010 82 174 80.5 04.11.2010 172.5 196 79.5 Táró spring Styx creek Komlós spring

Chemical composition of the waters Piper diagram Calcium-magnesium-bicarbonate hydrochemical facies Differences cannot be observed between the sampling locations, considering the joint effect of the parameters in the Piper diagram

Total Dissolved Solids (TDS) Chemical composition of the waters Piper diagram The TDS values in the observation wells are originally lower than in the cave’s other observed locations   Total Dissolved Solids (TDS) Location (mg/l) Béke well 592 "Ház-sarki" spring 635 Komlós creek 622 Komlós spring 631 Medence spring 554 Olympos pit 464 Olympos well 369 Styx creek 586 Styx well 393 Táró spring 536 Béke cave Baradla cave

Cluster analysis 1 (Dendogram of the Median values of the sampling locations) Examined parameters: Ca2+,Mg2+, Na+, K+,HCO3-,NO3-, SO42-, pH (80 data) Groups: Group 1 Olympos well, Styx well Group 2 Komlós creek, „Ház-sarki” spring Group 3 Olympos pit, Styx creek, Táró spring, Medence spring Group 4 Béke well, Komlós spring Group 1 Group 2 Group 3 Group 4 Baradla cave Béke cave Baradla cave Béke cave

Discriminant analysis (Median values) Béke well Komlós creek Komlós spring „Ház-sarki” spring Medence spring Táró spring Styx creek Styx well Olympos well Olympos pit 100% of original grouped cases correctly classified

Discriminant analysis (each sampling in time) Béke well Komlós creek Komlós spring „Ház-sarki” spring Medence spring Táró spring Styx creek Styx well Olympos well Olympos pit 85,1% of original grouped cases correctly classified The Discriminant analysis verified the classification

Box and Whisker diagrams of Groups 1-4 made from each sampling in time Ca2+ diagram HCO3- diagram

Cluster analysis 2 (Dendogram of the Median values of the sampling locations) Archive measurement data from: 1980-1983 (L. Maucha) and 2003-2005 (K. Fehér) Ca2+,Mg2+,pH,HCO3-,NO3-

Summary As expected water content is mostly Ca2+ and HCO3- which is specific to the natural state of the karst. Karst dissolution is the primary process that determines the chemical characteristics of caves’ creeks and springs. There are known caves with a separate water system that have creeks and thick sediment layers. The water system reacts to the surface weather conditions (precipitation, snow melting). The main ingredient of the cave sediment is quartz, so dissolution is minimal due to the stone-water interaction. The melt waters have the greatest effect on the configuration of the chemical characteristics and the water level in the observation wells. The water level in the wells decrease slowly – vulnerability! The water regime of the Béke cave has been changed since the 1980s In accordance to the water tracing experiments Outlook More observation wells will be constructed in both caves to better understanding of chemical characteristics and movements of the water in the sediments.

Acknowledgements József Kovács – Eötvös Loránd University Gábor Vid – Niphargus Cave Research Group Gábor Salamon, Péter Gruber – Aggtelek National Park

Thank You for your kind attention!