Assessment of Seawater Intrusion into Shallow Coastal Aquifer in Kanyakumari District, Tamilnadu, India

Abstract

Improved use of groundwater is often causing intrusion of seawater. The intrusion of seawater also takes place in coastal areas. In this analysis, the distribution and the levels of intrusion in the research area (Kanyakumari district, Tamilnadu, India) are determined. The test was done using random samples at a period of 15 days in which 30 different samples were taken in 5 different locations with a certain distance from the seashore, then chemical analysis including pH, electrical conductivity (EC), total dissolved solids (TDS), chloride, sodium, calcium, magnesium, carbonate, and bicarbonate water quality parameters were carried out. Chloride Bicarbonate Ratio was used for the calculation of the penetration rate of the seawater, and subsequently chloride and electric conductivity were defined as type and quality of water characters. The results showed that the shallow aquifer was intruded by seawater at several sample levels, which was included in the normal to high intrusion classification. The sea water intrusion was classified as freshwater to saltwater, the concentrations in chloride ranged from 159 to 6021 mg / L. The ratio of bicarbonate chloride was 0.28 to 21.46, normally above 15.5, indicating that groundwater was disturbed. As a result, in comparison to standards or other seawater intrusion indicators, Rajakamangalam-well 1 (RM-W1) has been affected by seawater intrusion highly.