A study on assessment of vulnerability of seawater intrusion to groundwater in coastal areas of Visakhapatnam, India

With an attempt to make a useful and convenient database, a case study has been conducted on impact of seawater intrusion to groundwater in the coastal localities of Visakhapatnam, India. Thirty groundwater samples were collected from varied locations covering at a stretch of 50 km from Bhemili to Paravada of Visakhapatnam coastal region. The groundwater samples were collected in pre- and post-monsoon in the year of 2017. The analytic studies to assess the quality of water were conducted. In comparison with WHO standards, chloride ion exceeded the permitted levels in (70% and 73%) of samples, calcium ion (23.3% and 13.3%) of samples, TDS (100% and 100%)of samples in pre- and post-monsoon seasons, respectively. The hydrochemical facies evolution diagrams and piper diagrams were used as tools to ascertain the factors and mechanisms responsible to vulnerability of groundwater due to seawater intrusion. As per the study, a type of mixed groundwater has been identified in the both the seasons. About 16% and 10% of samples were prone to seawater intrusion during pre- and post-monsoon seasons, respectively.