ABSTRACT
ABSTRACT: Groundwater in coastal regions is usually deteriorating by seawater intrusion. The towns and villages of Krishna delta are facing fresh groundwater problems because of transforming fresh groundwater to brackish/saline. Hydrochemical study has been carried out for the identification of hydrochemical parameters, which can be used for demarcating the fresh groundwater zones and identify the seawater intrusion processes. Groundwater analyses indicate that (1) HCO3/Cl molar ratio and TDS are fairly reasonable indicators for the identification of fresh groundwater in coastal aquifers, (2) Sr and B are found to be indicators for such delineation, and (3) Na vs. Cl, Na vs. EC, Cl vs. EC and Mg vs. TDS have been found reasonably good for the estimation of the intensity of seawater intrusion and their spatial and temporal variations. It is observed that the influence of brackish water is more in the South Krishna delta comparatively in the North Krishna delta where the percentage of fresh water wells is as high as 79%. A plot between HCO3/Cl molar ratio and TDS indicates good agreement with the results obtained from the trace elements (Sr and B) in the groundwater of the Krishna delta.
