© 2014 European Association of Geoscientists & Engineers 515 Near Surface Geophysics, 2014, 12, 515-521 doi:10.3997/1873-0604.2014007 * maxicosunny@gmail.com ** husin@utm.my Integrated geoelectrical and structural studies for ground- water investigation in parts of Abuja, North Central Nigeria Omeje Maxwell 1* , Husin Wagiran 1** , Noorddin Ibrahim 2 , Oha Ifeanyi Andrew 3 , Onwuka Obialo Solomon 3 and Soheil Sabri 4 1 Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Joho Bahru 2 Faculty of Defence Science and Technology, National Defence University of Malaysia, Kem Sungai Besi, 57000, Kuala Lumpur, Malaysia 3 Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria 4 Center for innovative Planning and Development (CiPD), Faculty of Built Environment, Universiti Teknologi Malaysia, 81310, Johor Bahru, Malaysia Received December 2012, revision accepted November 2013 ABSTRACT Abuja, the capital city of Nigeria, West Africa, is underlain by Precambrian basement rocks con- sisting mainly of porphyroblastic gneisses, granitic-gneisses, migmatitic gneisses, amphibolites, Pan-African granites and undifferentiated schists. The geology of Abuja, therefore, makes the groundwater conditions in the area very unpredictable. Geophysical surveys were carried out at 12 locations within and around the Gosa area and the results integrated with 88 lineament (fractures) extracted from hill-shaded Shuttle Radar Topography Mission (SRTM) data. The dominant frac- ture trend for the area is NNE–SSW and N–S, which corresponds to the Pan-African trends in the basement complex of Nigeria. It is observed that in the Gosa area, whereas fractures exist, they do not possess sufficient interconnectivity; this may have adversely affected the permeability of the fractured zone, resulting in the incidence of dry wells in the area. Moreover, evidence from inter- preted two-dimensional (2D) geoelectric sections reveals that in some parts of Abuja, the weath- ered overburden is not thick enough to support sufficient yield for a viable borehole. Interconnected fractures therefore become the desirable structural feature capable of improving the aquifer poten- tial. This study demonstrates the usefulness of integrating conventional vertical electrical sounding (VES) surveys with structural data derived from enhanced SRTM imagery in a hydrologically complicated terrain. fers (Satpatty and Kanugo 1976). The use of the vertical electri- cal sounding (VES) method is popular for groundwater investi- gation in both soft rock (sedimentary) and hard rock (igneous and metamorphic) terrains (De Beer and Blume 1985; Barongo and Palacky 1989; Mbonu et al. 1991; Shemang 1993). In the basement complex of Nigeria, extensive application of the geo- electrical method for groundwater investigation has been report- ed (e.g., Zohdy, Eaton and Mabey 1974; Pulawski and Kurth 1977; Acworth 1987; Olorunfemi and Okankune 1992; Olorunfemi and Fasuyi 1993; Edet and Okereke 1997; Nur and Ayuni 2004). Application of remotely-sensed data for groundwater investi- gation is becoming increasingly popular, especially in areas where conventional methods are inadequate in accurately demar- cating hydrologic zones. Examples include the works of Galnett and Gardner (1979), Edet et al. (1994), Bala (2001) and Bala, Batalan and De Smedt (2000). In a few case studies it has suc- INTRODUCTION Basement rocks do not inherently make good aquifers (Acworth 1987; Manda, Mabee and Boutt 2006). The hydrogeologic char- acteristics of basement rocks are only enhanced when the rocks are fractured and/or when they are weathered (Clark 1985; Wright 1992). The conditions are better enhanced when the rocks are overlain by thick overburden, which could form con- siderable zones of weathered rock aquifer. Groundwater poten- tials of a basement complex area are often determined by geo- physical means, which determines the thickness of the overbur- den and the network of fractures that may exist in the area (e.g. Mendoza and Dahlin 2008). Geophysical surveys are also important for groundwater investigation in basement areas in view of the discontinuous (localized) nature of basement aqui-