Vertical electrical sounding (VES) and multi-electrode resistivity in environmental impact assessment studies over some selected lakes: a case study

• Published in: Environmental earth sciences Vol. 65; no. 3; pp. 881 - 895
• Main Authors: Sundararajan, N., Sankaran, S., Al-Hosni, T. K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2012; Springer Nature B.V
• Subjects: Biogeosciences; Clay; Earth and Environmental Science; Earth Sciences; Effluents; Electric resistance; Environmental impact; Environmental Science and Engineering; Freshwater; Geochemistry; Geology; Groundwater flow; Groundwater storage; Hydrology/Water Resources; Lakes; Original Article; Sewage; Shallow water; Silt; Surface water; Surface-groundwater relations; Terrestrial Pollution; Water analysis; Water pollution; Water sampling; Water table; India, Andhra Pradesh, Hyderabad; Indonesia, Sumatera, Musi R; India; Drainage; Clay; Vertical electrical sounding; Pollution; Groundwater; Multielectrode system; Resistivity; Silt; Lithologs; Chemical effluents
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-011-1132-7

A combined geophysical investigation consisting of vertical electrical sounding (VES) and multielectrode system was carried out to map the subsurface resistivity in all major lakes which are highly polluted by the discharge of sewage and other chemical effluents in greater Hyderabad, India. The structural features identified in the study area play a major role in groundwater flow and storage. The interpretation of geophysical data and lithologs indicates that a silt/clay zone (predominantly silt) has a thickness of 5–10 m all along the drainage from Patelcheruvu to the Musi River. The silt/clay zone inferred close to the lakes is a mixture of clay, silt and sand with more silt content as indicated from the lithologs during drilling. The low resistivity values obtained can be attributed to the pollutant accumulated in the silt which can reduce the resistivity values. Further, the TDS of the water samples in these wells are more than 1,000 mg/l which further confirms the above scenario. The pollution spread is less in the upstream areas whereas it is more in the downstream which can be attributed to the shallow water table conditions and also due to the interaction of surface water and groundwater.