Prof.S.Chidambaram Department of Earth sciences Annamalai University India A review on the hydrogeochemical research and its future perspectives

IsotopesSGDGeophysicalLithologicalHYDROGEOCHEMISTRYGeneral ionsRS GISStatistical Geochemical modeling QualityProcess Heavy metals Ion SpecificUtility

Quality - Utility

SEASONSpHECTDSCaMgNaKClHCO 3 SO 4 H4SiO 4 PO 4 NO 3 SPRM SPOM DPRM DPOM WHO < BIS Drinking water quality

Wilcox diagram Agricultural water quality

WATCLAST- program Other water quality parameters (Chidambaram et al 2004)

Quality – Ion Specific Fluoride Uranium Arsenic

Fig: 5.31a. Spatial distribution of F - of NEM Fig: 5.31b. Spatial distribution of F - of POM Fig: 5.31c. Spatial distribution of F - of SUM Fig: 5.31d. Spatial distribution of F - of SWM Fluoride

Uranium

Spatial distribution of As for groundwater samples (All values in µg/l)) Maximum, Minimum and Average of Arsenic (All values in µg/l)) Arsenic

Process – General Ion

Piper facies diagram Modified Doneen’s plot Gibbs plot Relationship of log pCO 2 to Ionic Strength Standard plots

Thermo dynamic stability

Sea water intrusion

Saturation index

Process – Lithology

Relative mobility of cations in Rock Water Interaction studies Relative mobility

Lithological charecterisation

Process – Metals

Process – RS and GIS

Parameters Classification based on quality Standards by BIS & WHO Measured FormationPRMSWMNEMPOM GoodModerateUnsuitableDesirablePermissible Min.Max.Min.Max.Min.Max.Min.Max. EC (µS/cm) < – 3125 > Alluvium Upper Cuddalore Lower Cuddalore Cretaceous TH (Ca&Mg) (mg/l) < > Alluvium Upper Cuddalore Lower Cuddalore Cretaceous Sodium (mg/l) < > Alluvium Upper Cuddalore Lower Cuddalore Cretaceous Chloride (mg/l) < > Alluvium Upper Cuddalore Lower Cuddalore Cretaceous Sulphate (mg/l) < > Alluvium BDL Upper Cuddalore BDL Lower Cuddalore BDL Cretaceous Alkalinity (mg/l) < > Alluvium Upper Cuddalore Lower Cuddalore Cretaceous DOC (mg/l) (ODWSOG2006, Spruill et al. 1997) < >5 Alluvium 16.98BDL Upper Cuddalore Lower Cuddalore Cretaceous Index (Decision Criteria)321

Flow chart representing the preparation of the vulnerability maps Vulnerability studies

Groundwater vulnerability index map of the Alluvium aquifer overlay on Landuse (Thilagavathi 2013) Vulnerability studies

Process – Modeling

Process – Statistics

Post monsoon CAMGNAKCLHCO3SO4PO4SIO2PHTDS CA1 MG NA K CL HCO SO PO SIO PH TDS MG NA K CL HCO SO PO SIO PH TDS Saline intrusion Recharge and weathering of K feldspar Anthropogenic Seasonal -Correlation and Factor analysis

CAMGNAKCLHCO3SO4PO4SIO4PHTDS CA1.00 MG NA K CL HCO SO PO SIO PH TDS CA MG NA K CL HCO SO PO SIO PH TDS Ion exchange S.W.intrusion Fertilisers recharge Pre monsoon Correlation and Factor analysis

Seasonal and the Spinal species

Factor score

Process – Isotopes

Dissolved organic carbon

Isotope and climate

Process – SGD

Process – Geophysical

Surface Geophysical methods

Spatial representation of reisitivty values

Fig. Three-dimensional variation of litholog and resistivity (  m) for four locations Thavalakuppam, Chinna Verampattinam,Thavalakuppam and Nallavadu in the study area Creation of 3D fence to correlate

Conceptual models

Future perspectives Climate Change Geochemical baseline Integrated techniques

Climate change Longterm geochemical data in correlation with landuse and water level changes Pore water stuides CFC, Tritium models and Helium

Geochemical baseline Tritium models Microbial characterization with metal/inorganic ion Noble gases Organic Geochemistry Colloidal interface with metals and ions Interlinking of components in hydrological studies

Integration of relevant techniques

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