GEOELECTRICAL INVESTIGATION OF GROUNDWATER POTENTIAL OF ADMINISTRATIVE BLOCK AT PERMANENT SITE, FEDERAL UNIVERSITY DUTSIN-MA, KATSINA STATE, NIGERIA

Abstract A  geophysical  survey  for  groundwater  resources  was  carried  out  in  the  administrative  block  of Federal  University  Dutsin-Ma,  permanent  site.  This  was  successfully  done  by  employing  the electrical  resistivity  method  to  investigate  the  water  table  variations,  the  depth  to  basement, thickness of weathered basement, thickness of aquifer and area suitable for boreholes establishment within  the  areas  covered  with  the  application  of  Schlumberger  arrangement.  ABEM TERRAMETER  SAS  300  was  the  principal  instrument  used  in  this  survey.  A  total  of  two transverses  with  five  VES  stations  along  each  traverse,  having  separation  of  20  m  apart,  were investigated. It has a maximum current electrode separation (AB/2) of 160 m. Three to four layers were observed namely; Top layer, weathered layer, fractured layer, and fresh basement layer. First layer  has  resistivity,  depth  and  thickness  range  of  101-1573  Ωm,  13.2-36.6  m  and  6.06-17.3m respectively.  Second  layer  has  a  range  of:  resistivity,  2.36-3040  Ωm;  depth,  0.406-20.m  and thickness, 0.0409-20 m. Third layer has a range of: resistivity, 190-3194 Ωm; the depth, 0.19-111 m and thickness, 0.19-107 m. Fourth layer has a resistivity range of 26.3-896 Ωm; its depth, 0.366-2.23 m and thickness, 0.366-1.22 m. While the fifth layer has resistivity, depth and thickness range of: 95.7-1711 Ωm, 0.44-50.6 m  and  0.44-49 m. The VES curves  were interpreted  using IPI2Win resistivity  computer  software  and  contour  Maps  were  produced  using  SURFER  10  computer software. The  results  of  the  interpreted VES  data showed that the saturated groundwater  bearing layer (aquifer) lie within the weathered and fractured basement of the predominantly four-layered structure. VES 01, 02 and 03 have high potential for groundwater. However, the sitting of borehole can be done on VES 03 because it has the ability to retain and sustain portable water. 

Keywords: Groundwater, Borehole and Resistivity, vertical electrical sounding VES, depths to basement.