Delineation of Saltwater and Freshwater Interphasein Beach Groundwater Study Using 2D ERITechnique in the Northern Sector of the Gulf of Mannar Coast, Tamilnadu
Antony Ravindran A1*, Ramanujam N2 and Sudarsan R3
1Department of Geology, Geophysics Research Lab, Manonmaniam Sundaranar University,V.O.Chidambaram College,Thoothukudi
2Pondicherry University, Disaster Management, Andaman
3Indra Ghandi National Open University, New Delhi
*Correspondence E-mail: [email protected]
Key Words: Freshwater, Saline Water, Resistivity, 2D ERI, Gulf of Mannar
Received February 26th, 2012; Accepted March 3rd, 2013; Published April 14th, 2013; Available online April 20th,2013
Abstract
The aim of the study is about how beaches in the study area act like a sponge but the groundwater along the beach is very dynamic. The flow direction of the beach groundwater is mainly governed by the physical and geological characteristics of the beaches as well as the waves and tide conditions in the sea. In the northern sector of the study area there are a number of open wells close to the sea being used to draw water for portable purposes by the villagers settled along the beaches. Such field observation suggests that the seawater intrusion is limited in some areas of the study area. Through the 2D Electrical Resistivity Imaging (ERI) technique, an attempt is made to understand the interface zone of the seawater intrusion and the land groundwater along the beach groundwater table. This technique involves the transition of electrical currents into the ground between two electrodes and measuring of voltage between the other two electrodes in transect, the profile with predetermined interval of distances either parallel or perpendicular to the coastal zone is decided. CRM-500 resistivity measuring instrument, multicore cable, stainless steel electrodes are the hardware and “RES2DINV” is the software that were used for conducting the 2D Electrical Resistivity Imaging study.