Mapping of unconfined aquifer using vertical electrical sounding (VES) at Lagos State University (Lasu), Ojo

By A.S Ogungbe, J.A Olowofela, O.O Oresanya, A.A Alabi

Abstract

Geophysical investigation involving the use of electrical resistivity was carried out at LASU, Ojo with a view to mapping out its unconfined aquiferous zone. A total of eight vertical electrical soundings (VES) were taken and the H and K curves were used in matching the graphs. The results acquired from the survey were subjected to iteration software (win Resist) which delineated four geo-electric layers namely: topsoil, sand, sandy clay and clay. The  results observed in VES1-4(AA) and VES 5-8(AA) establish that unconfined aquifer is between the thickness of 0.5m-2.9m with resistivity ranging from 102.1-322.9  in both geo-electric sections.

 

Key Words : Unconfined Aquifer, groundwater, water table, artesian well.

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