A study on identification of submarine groundwater discharge in northern east coast of India

Abstract

In the present study, an attempt has been made to identify submarine groundwater discharge in two districts of West Bengal, India through in situ radon (222Rn) monitoring. The investigations indicated relatively high 222Rn activities (average: 4.98 ± 0.83 kBq m-3) in the coastal waters revealing considerable submarine groundwater discharge (SGD). The electrical conductivity (EC) of groundwater ranged from 850-5000 μS cm-1 with an average of 1385 μS cm-1. The variation in Radon and EC corresponds to discharge of fresh groundwater to the sea. The SGD is generally a combination of fresh groundwater and re-circulated seawater which is controlled by hydraulic gradient in the adjacent aquifer, and varying tidal conditions in the coastal waters. The study indicates the possibility of identifying groundwater discharge through long coastline in India. The SGD can be harnessed for meeting human needs wherever required.