Groundwater Exploration Using Electrical Resistivity Method A Case Study In Federal Capital Teritory (FCT) Abuja. Nigeria

Kasidi S.

Eighteen resistivity data points were sounded in the study area with ABEM Terrameter,  Maximum electric current half spacing attained for each point 100m away. Schulumbergers array was used for acquisition of data after which two methods of interpreting the data were used, qualitatively and quantitatively the raw data were interpreted with IXD1 software. Possible groundwater  potential areas were detected.  Out of the 18 VES points, VES 1, 5, 7, 9, 11, 12, 15, 16, 17 and 18 have groundwater potentials at depth ranging from 40 m – 80 m. The thickness of the aquifers with such potentials ranges from 37 m – 65 m.  VES 2, 3, 4, 6, 8, 10, 13, 14, and 15 lacks fractured zone as such groundwater cannot be explored at these VES points. The X, Y, Z, data file was imported into Surfer9 software for resistivity mapping and contouring using kriging interpolation algorithm. The resistivity of the first layer of these points with groundwater potentials ranges from 500 ohm –m to 9000 ohms – m. While the resistivity value of the second layer ranges from 50 ohm – m to 800 ohm – m, and the resistivity value of the third layer ranges from 80 ohm – m to 700 ohm – m. The maps  that were plotted was done using the resistivity values of the first, second and third layer of VES points with groundwater potentials while the elevation above sea level was used to produce  map of the  study area and VES points.