Geological Behavior (GBR) 5(2) (2021) 59-66 Quick Response Code Access this article online Website: www.geologicalbehavior.com DOI: 10.26480/gbr.02.2021.59.66 Cite The Article: Kazeem O.Olomo , Oluwatoyin K. Olaleye , Temitayo O. Ale, Michael T. Asubiojo , Oluyemi E. Faseki (2021). Integrated Geophysical Mapping of Groundwater Aquifer for Spatial Distribution of Groundwater Development in Iperindo and Its Environs, Southwestern Nigeria, Geological Behaviour 5(2): 59-66. ISSN: 2521-0890 (Print) ISSN: 2521-0491 (Online) CODEN: GBEEB6 RESEARCH ARTICLE Geological Behavior (GBR) DOI: http://doi.org/10.26480/gbr.02.2021.59.66 INTEGRATED GEOPHYSICAL MAPPING OF GROUNDWATER AQUIFER FOR SPATIAL DISTRIBUTION OF GROUNDWATER DEVELOPMENT IN IPERINDO AND ITS ENVIRONS, SOUTHWESTERN NIGERIA Kazeem O.Olomo a * , Oluwatoyin K. Olaleye b , Temitayo O. Ale a , Michael T. Asubiojo a , Oluyemi E. Faseki b a Department of Earth Sciences, Adekunle Ajasin University, Akungba-Akoko, Nigeria b Department of Applied Geophysics, Federal University of Technology, Akure, Nigeria *Corresponding author email: kazeeem.olomo@aaua.edu.ng This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ARTICLE DETAILS ABSTRACT Article History: Received 06 October 2021 Accepted 08 November 2021 Available online 23 November 2021 Assessment of groundwater potential of Iperindo area, Southwestern Nigeria was conducted by mapping spatial distribution of groundwater availability within the area and consequently locating areas of groundwater reserve to serve the community and its environs. This was achieved by integrating geophysical techniques involving landsat ETM-7 satellite data, aeromagnetic data, VLF-EM and electrical resistivity methods to delineate subsurface structures, understand the direction of groundwater flow, and detect the depth to groundwater aquifer. The result of landsat and aeromagnetic revealed some lineament intersection approximately NE-SW direction and interpreted to be potential sites for groundwater development. VLF-EM revealed geologic structures of significant hydrogeological importance at depths of 40 m to 200 m. Vertical electrical sounding (VES) confirmed high groundwater prospect in the areas with estimated depth to water table between 30 m and 100 m. The integrated results of the study revealed adequate groundwater spatial distribution for effective groundwater development in the area. KEYWORDS aeromagnetic, aquifer, geologic structure, hydrogeology, landsat. 1. INTRODUCTION Water is a basic need critical to human life because it contains nutrients that help human body functionality. Its importance includes the support for food digestion, absorption, nutrients use and transportation, and elimination of toxins and wastes from the body. Adequate provision of safe domestic water is a health protecting measure. The quality and quantity of water people use depends on the ease to access it. Improving the access to safe water supply is a major health challenge for the World Health Organisation (WHO) and United Nations Children’s Fund (UNICEF). Availability of potable water is one of the major challenges in Nigeria and other developing countries. Statistics show that access to improved water was 39 % in 1999, while access to safe water was 50% in 1995 and 54% in 1999 in Nigeria (Federal Government of Nigeria and United Nations Children’s Fund, 2001). Rapid mining activities by the illegal miners currently witnessed at study area have resulted into poor access to potable water. Protected dug wells and borehole water pumps are not readily available in this area. People largely depend solely on water from streams and hand-dug wells for both commercial and domestic uses. Apart from untold hardship that people are facing owing to inadequate quality water, the available sources of water are vulnerable to pollution as result of runoff water from the processed mined gold. This has made the people to be prone to water- borne related diseases such as diarrhea, intestinal worms, cholera, dysentery and typhoid fever. One of the scientific recommended approaches to improve access to potable water is to carry out geological and geophysical investigation to locate groundwater site that is free from contamination before placing a borehole (Olomo, 2021). Groundwater is generally controlled by weathered and fractured basement rocks especially in the basement area (Wright, 1992; Olorunfemi and Fasuyi, 1993). The basement aquifers are often discontinuous laterally and vertically due to the presence of fault (Satpathy and Kanugo, 1976). These natures of the basement aquifer system make the adoption of geophysical investigations method possible to unravel the subsurface geology, weathered depth and structural setting. Several Geophysical methods such as electrical resistivity, gravity, magnetic, seismic and electromagnetic have proven to be reliable through which hydrogeological significant features can be mapped (Eaton and Watkins, 1970; Vanderberghe, 1982). Integration of aeromagnetic and remote sensing methods data recently becomes highly effective tool for investigating groundwater resource exploration (Batista-Rodriguez et al., 2017; Hung et al., 2005). Aeromagnetic method has been found to be very successful in delineating various subsurface formations due to relatively high susceptibility contrast between basement rocks (Emujakporue et al., 2017; Osinowo et al., 2013; Steinich et al., 1999; Srivastava, 2002). Electrical resistivity method provides a significant resistivity contrast between deposit overburden and the underlying bedrock (Ako and Olorunfemi, 1989). Very Low Frequency Electromagnetic (VLF–EM) method is useful in groundwater investigation in basement terrain, to appreciably map thick overburden and geological structures such as fault and fracture zones that are favorable to groundwater accumulation (Amadi and Nurudeen, 1990; Olorunfemi et al., 1995; McNeill, 1980; Palacky et al., 1981).