GEOPHYSICAL INVESTIGATION OF GROUNDWATER POTENTIAL IN MILLENNIUM CITY HOUSING ESTATE KADUNA, NIGERIA USING ELECTRICAL RESISTIVITY METHOD

Abstract

Lack of potable drinking water supply remains one of the main challenges of residents of Millennium City Housing Estate, Kaduna, Nigeria. The groundwater potential of the area was investigated using vertical electrical sounding (VES) method. A total number of 36 vertical electrical sounding VES points were used for the entire investigation using schlumberger array and the data obtained were analyzed using curve matching and computer iteration techniques. The data revealed both a 3- layer (KHand H Curve types) and 4-layer (H-curve type) only for the area. In the 3-layer system, the apparent resistivity of the first layer ranged from 31.0 Ωm to 57.5 Ωm with a corresponding thickness of 0.8 m to 1.6 m. The second layer has apparent resistivity value ranged from 13.6 Ωm to 907.9 Ωm with a corresponding thickness range of 4.4 m to 22.8 m while the third layer layer has resistivity values ranging from 1087.1 Ωm to 1477.2 Ωm with an infinite depth. For the four (4) layered model curves, first layers resistivity ranged from 131.7 Ωm to 208.5 Ωm, with a corresponding thickness ranged from 0.8 m to 1.0 m. The resistivity of the second layers ranged between 28.8 Ωm to 29.9 Ωm with a corresponding thickness ranged from 5.1 m to 16.3 m. The third layer resistivity ranged from 111.4 Ωm to 287.2 Ωm with a corresponding thickness ranged from 8.2 m to 22.6 m. The forth layer has a resistivity value ranging from 1044.3 Ωm to 1833.6 Ωm with an infinite depth. An integration of both isopach and iso-resistivity maps for both the 3-layer model curves and 4- layer model curves indicates that most of the north/west parts of the study area have low apparent resistivity values and thick overburden which implies good groundwater potential while the southern portion has a little higher resistivity values and shallow overburden, an indication of poor groundwater potential. Future boreholes in the area should reached an effective depth of 40 m to 55 m depth and the borehole be supervised by a certified hydrogeologist or geophysicist for optimum groundwater yields. Pumping test should be carried out in order to ascertain the size and type or quality of submersible pump to be installed for optimum yield.