|
International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 8, No. 3, 2011, pp. 483-492
|
Bioline Code: st11044
Full paper language: English
Document type: Research Article
Document available free of charge
|
|
International Journal of Environment Science and Technology, Vol. 8, No. 3, 2011, pp. 483-492
en |
Assessment of seawater mixing in a coastal aquifer by high resolution electrical resistivity tomography
Sathish, S.; Elango, L.; Rajesh, R. & Sarma, V. S.
Abstract
Seawater intrusion is a major problem in urbanized coastal regions of India which is due to over exploitation of groundwater for various purposes. This study was carried out with the objective of assessing the zone of mixing between seawater and groundwater in the coastal aquifer in south of Chennai, Tamil Nadu, India using high resolution electrical resistivity tomography. High resolution electrical resistivity tomography was carried out in five profiles perpendicular to the sea using IRIS make SYSCAL Pro-96 system with 2.5 m or 5 m inter-electrode separation. The maximum length of the profile was 170 m which resulted in a depth of investigation of 28.7 m. The apparent resistivity measured in this area varies from 0.3 ohm-m to 30,000 ohm-m. The apparent resistivity of saturated zone decreases towards the sea, indicating the influence of seawater. This was also confirmed by measuring the electrical conductivity of groundwater, which gradually increases from 156 μS/cm to 3430 μS/cm towards the sea. Further, the concentration profiles of electrical conductivity, sodium, chloride and chloride / bicarbonate ratio are compared with the high resolution electrical resistivity tomography profile. The distance of influence of seawater is comparatively high in northern part than in southern part of the area. The high resolution electrical resistivity tomography was effectively used to determine the effect of seawater mixing with groundwater.
Keywords
Electrical conductivity; Groundwater quality; Lithology; Seawater intrusion
|
|
© Copyright 2011 - Center for Environment and Energy Research and Studies (CEERS) Alternative site location: http://www.ijest.org
|
|