ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY & ENVIRONMENT AZOJETE September 2022. Vol. 18(3):357-376 Published by the Faculty of Engineering, University of Maiduguri, Maiduguri, Nigeria. Print ISSN: 1596-2644, Electronic ISSN: 2545-5818 www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 345 ORIGINAL RESEARCH ARTICLE GEOPHYSICAL MAPPING OF AQUIFER POTENTIAL ZONES USING HYDRAULIC PARAMETERS IN LOKOJA AND ENVIRONS, NORTH-CENTRAL, NIGERIA O. A. Omali* and J. T. Arogundade Department of Earth Sciences, Kogi State University Anyigba, Nigeria *Corresponding author’s email address: omaliaurelius@yahoo.com 1.0 Introduction The importance of water as a basic resource for human activities cannot be over-emphasized. It is needed for cooking, washing, cleaning, construction activities, manufacturing etc. The qualitative and quantitative assessments of its sources are therefore necessary to ensure its availability in the study area. Lokoja has witnessed an upsurge in human and infrastructural growth since it became the capital of Kogi State in 1991. The demand for potable water supply for various needs has grown significantly. The State Water Board is currently supplying about 2.7 million gallons of water per day to Lokoja and its environs as against the 10 million gallons needed per day (Omali, 2012). Successive governments in Kogi state, the United Nation Children Emergency Fund (UNICEF), Water and Environmental Sanitation (WES) and private developers have provided a number of boreholes to augment the water supply in the area. The major source of water for domestic and industrial uses in the study area is groundwater. The methods of exploration are grouped into surface geological, subsurface geological, surface geophysical and subsurface geophysical methods. The techniques of water resources evaluation require an understanding of the concept of groundwater yield, the quantity and quality of ARTICLE INFORMATION ABSTRACT This research is aimed at delineating the groundwater potential in Lokoja and environs using Dar Zarrouk parameters. The study area is part of the Basement Complex of South-western Nigeria and the Lokoja sub-basin of the middle Niger sedimentary basin, on area coverage of about 400km2. Thirty-five (35) vertical electric soundings (VES) using Schlumberger array method with the aid of ABEM Signal Averaging System (SAS) Terrameter were used for the data acquisition. The result of the interpretation shows four geo-electric layers. The resistivity soundings results revealed that about 4 curve types were identified in the study area namely AA, HA, A and H type with the lithologic layers varying from 3 to 4 and consisting of varying resistivity and thicknesses across each VES point. The geo-electric sections revealed that the major aquifer systems in the study area are weathered basement and weathered/fractured basement. The longitudinal conductance computed that range from 0.00904951 to 0.7814713 Ω-1indicates that the aquifers in the area have poor to moderate protective capacity whereas transverse resistance that range from 24.5841 to 7290.15Ω indicates very low groundwater development class. Hydraulic conductivity with a range of 0.36757M/day to 56.86754M/day and transmissivity values with a range of 4.4548 to 917.273M2 /day indicate very low to moderate aquifer capable of sustaining moderate communities. © 2022 Faculty of Engineering, University of Maiduguri, Nigeria. All rights reserved. Submitted 14 April, 2021 Revised 28 April, 2022 Accepted 30 April, 2022 Keywords: Hydraulic conductivity Transmissivity Vertical electrical sounding transverse resistance longitudinal conductance http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com mailto:omaliaurelius@yahoo.com mailto:omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 358 groundwater in the hydrogeological environment. The method of exploitation of groundwater involves the drilling and installation of pumps and piezometers and abstraction of water from the subsurface. The concept of Dar Zarrouk parameters can be used to assess the groundwater potential of an aquifer, such that, when the thickness and resistivity of subsurface layer are known, its transverse resistance and longitudinal conductance can be estimated (Egbai and Iserhien- Emekeme, 2015; Bello et al., 2019). According to Egbai and Iserhien-Emekeme (2015) and Bello et al. (2019), the concept of Dar Zarrouk parameters can be used to assess the groundwater potential of an aquifer, such that, when the thickness and resistivity of subsurface layer are known, its transverse resistance and longitudinal conductance can be estimated. Over the years, the Dar Zarrouk Parameters primarily derived from layer resistivity and thickness, have proven to be important in understanding the spatial distribution of aquifer’s hydraulic parameters, assessment of contaminated landfills and subsurface investigation of engineering structures (Udoinyang and Igoekwu, 2012; Okiongbo and Oborie, 2015) which can be obtained from surface geo-electric soundings, have proven to be important in understanding the spatial distribution of aquifer hydraulic parameters. Dar Zarrouk parameters of an aquifer including transverse resistance, reflection coefficient and coefficient of anisotropy can be established with resistivity measurement of an aquifer (Heigold et al., 1979; Nwosu et al., 2014; Kwame et al., 2019). Nwosu et al. (2014) derived analytical relations between aquifer transmissivity and transverse resistance. In the same vein, Kwami et al. (2019) were able to delineate groundwater potential zones in Gombe and its environs using Dar Zarrouk parameters. There are several water boreholes in Lokoja metropolis and environs. However, majority of these boreholes are not functioning as expected due to low yield and poor maintenance. There are several boreholes scattered throughout the Lokoja metropolis and environs however, majority of these boreholes are not functioning as expected due to low yield and poor maintenance. Some of the physical properties of an aquifer such as hydraulic conductivity and transmissivity that control the flow and yield of groundwater can be adequately estimated using Dar Zarrouk parameters (Bello et al., 2019). The aim of this work therefore, is to use Dar Zarrouk parameters to assess the groundwater potential of the aquifers and ascertain aquifers of good yield and productivity in the Basement Complex rock of Lokoja metropolis. 1. Study area The area is located between latitudes 7o 441 3311N and 7o 521N and longitudes 6o 381 611E and 60 481E. It lies on part of the Basement Complex of South-western Nigeria and the Lokoja sub- basin of the middle Niger sedimentary basin, on area coverage of about 400 km2 as shown in Figure 1. The major settlements in the area include Lokoja, Adankolo, Lokongoma, Kabawa, Ganaja, Zangodaji, Sarkin Noma and Felele. The study area is accessible through a trunk “A” road from Abuja to Lokoja and Okene to Lokoja and a trunk “B” road from Ajaokuta to Lokoja. It is also accessible by ferry via the River Niger from Shintaku. The area is populated by several ethnic groups and it is thus very typical of the middle Belt region of Nigeria. file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 359 Figure 1: Map of Nigeria showing Lokoja, the study area 2.1 Geology and hydrogeology of the study area The study area falls into two geological domains, viz, the Basement Complex of South-western Nigeria and the Lokoja Sub-basin of the mid Niger-basin. The North-Western, western and South-western parts of the study area are predominantly covered by Migmatite, whereas the Northern part is composed of biotite hornblende gneiss. In addition, the South and South- eastern part are dominated by undifferentiated older granite, mainly Porphyroblastic granite, granite gneiss with porphyroblastic gneiss while the South also composed of outcrops of fine grained biotite granite. The central portion of the area is made of feldspathic sandstone and siltone. However, thick alluvium deposits trend from the Northeast to South of the area along the Benue and Niger drainage system (Figure 2). The study area falls into two geological domains, viz, the Basement Complex of South-western Nigeria and the Lokoja Sub-basin of the mid Niger-basin (Abimbola, 1997; Akande et al., 2005). The North-Western, western and South-western parts of the study area are predominantly covered by Migmatite, whereas the Northern part is composed of biotite hornblende gneiss. In addition, the South and South- eastern part are dominated by undifferentiated older granite, mainly Porphyroblastic granite, granite gneiss with porphyroblastic gneiss while the South also composed of outcrops of fine grained biotite granite as shown in Figure 2, the central portion of the area is made of feldspathic sandstone and siltone. However, thick alluvium deposits trend from the Northeast to South of the area along the Benue and Niger drainage system (Udenzi and Osazuwa, 2004). Hydrogeologically, the area is drained by river Benue and river Niger in addition to the Meme River, which is a tributary of river Niger. Groundwater in the study area is recharged by these drainage systems and from meteoric water during rainfall. Prolific aquifers are sourced from weathering of the Basement rocks and fractures of the rock (Omali, 2014). http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 360 Figure 2: (a) Generalized geological map of Lokoja area (Omada et al., 2015) (b) Detailed geological map of the study area (Omali, 2014) 3. Materials and Methods A total of thirty-five (35) vertical electrical soundings (VES) were carried out in this study. Terrameter SAS 300C was used to carry out the resistivity measurement in the field. Schlumberger configuration was adopted with maximum half-current electrode spread (AB/2) of 60m while the half potential electrode separation (MN/2) was maintained between 0.5m and 7.5m. The VES curves were quantitatively interpreted by partial curve matching and computer iteration techniques, using resound, a computer programme based on linear filter theory (Zohdy, 1989). The principle of the resistivity method is that electric current is passed into the ground through two outer electrodes, and the resultant potential difference is measured across two inner electrodes that are arranged in a straight line, symmetrically about a centre point The potential difference to the current ratio is displayed by the terrameter as resistance. A geometric factor in meters (m) is calculated as a function of the electrode spacing. The resistance readings obtained from the Terrameter is multiplied by this factor to give an apparent resistivity value. The electrode spacing is progressively increased, keeping the centre point of the electrode array fixed. The electrical resistivity survey was carried out to determine aquifer types. 3.1 Hydraulic parameters The term Dar Zarrouk parameters has been used to describe the relationship between the longitudinal unit conductance and transverse resistance. Longitudinal conductance (Si) =∑ ℎ𝑖/ϼ𝑖𝑖=1 (1) hi = layer thickness measured in meters (m) pi= aquifer resistivity in measured in ohms meter (ῼm) Transverse resistance (R) = ∑ ℎ𝑖 ϼ𝑖𝑖=1 (2) file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 361 The longitudinal conductance (Si) in equation (1) is a measure of the impermeability of a rock layer (Billing, 1972; Mbonu et al., 1991). Transmissivity (Tr) = K.hi (3) Tr is measured in meter square per day (m2day) K is the Hydraulic conductivity measured in metes per day (m/day) hi is the layer thickness of the aquifer measured in meters (m) Hydraulic conductivity (K) = 386.40Rrw -0.93283 (4) Rrw is the layer resistivity measured in ohms meter An n-layer DZ curve is composed of n branches, each of which terminates at a point whose coordinates, Lm and pm, represent the thickness and resistivity of a fictitious layer that replaces all the overlying layers. According to Eqns. (3) and (4), the coordinates of any given point on a DZ curve are a function of the thicknesses and resistivity of layers that exist above a given depth, D, but they are not related to the thicknesses and resistivity of layers beneath that depth. In contrast, on a VES (vertical electrical sounding) curve, the coordinates of a given point are calculated from an integral expression (Stefanesco et al., 1930) that involves all the thicknesses and resistivity in the section, and, therefore, they are not related to particular depth. The longitudinal conductance (S) is a measure of the impermeability of a rock layer (Billing, 1972). Electrical anisotropy is a measure of stratified rock which is generally more conductive in the parallel plane than in the perpendicular plane (Malick et al., 1973; Cihan et al., 2014). For a sequence of horizontal, homogeneous and isotropic layers of resistivity ℯ1 and thickness hi. Eqs. (v) and (vi) defined the Dar Zarrouk parameters (longitudinal conductance S and transverse resistance TR) as follows: Equation 1, 2, 3 and 4 are only true for a sequence of horizontal, homogeneous and isotropic layers of resistivity ℯ1 and thickness hi (Malick et al., 1973; Cihan et al., (2014) and Kwami et al., 2019). The methods discussed above were employed to generate Vertical electrical sounding data. http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 362 4. Results The results of the analyses are as presented in Tables 1-9 and Figures 3-6 Table 1: Vertical Electrical Sounding Data VES No. Location Coordinates Layer No. Resistivity(Ohm-m) Thickness (m) Inferred Layer Remark 1 Ganaja BH1 N 070 4433” E0060 44’ 33” 1 161.45 1.09 Topsoil (clay/laterite 2 17.87 10.83 Weathered basement(aquifer) Aquiferous unit 3 5721.11 - Competent basement 2 500 unit (BH1) N 070 44’ 56.6" E0060 44’ 24.7” 1 538.83 1.07 Topsoil (clay/laterite 2 83.19 12.07 Weathered basement(aquifer) Aquiferous unit 3 6928.32 - Competent basement 3 500 unit (BH2) N 070 45’ 24.7” E060 44’ 24.7” 1 190.66 2.76 Topsoil (clay/laterite 2 48.35 8.89 Weathered basement(aquifer) Aquiferous unit 3 1230.23 - Competent basement 4 200 unit (BH1) N 070 45’ 33.1" E060 44’ 21.1” 1 648.47 2.9 Topsoil (clay/laterite 2 18.35 14.34 Weathered basement(aquifer) Aquiferous unit 3 1298.98 - Competent basement 5 200 Unit (BH2) N 070 45’ 48” E060 44’ 15.5” 1 485 3.87 Topsoil (clay/laterite 2 15.57 12.23 Weathered basement(aquifer) Aquiferous unit 3 7724.31 - Competent basement 6 Phase I (BH1) N 070 47’ 24.7” E 060 43’ 22.3” 1 20 8 Topsoil (clay/laterite 2 41.5 7.5 Clay/laterite 3 277.6 3.7 Weathered basement(aquifer) Aquiferous unit 4 491.89 - Competent basement 7 Phase I (BH2) N 070 47’ 29.3” E 060 43’ 33” 1 75 14 Topsoil (clay/laterite 2 166.23 3.6 Weathered basement(aquifer) Aquiferous unit 3 260.4 - Competent basement 8 Phase II (BH1) N 070 48’ 4.7” E060 41’ 55.2” 1 111.99 3.09 Topsoil (clay/laterite 2 6.81 3.61 Weathered basement(aquifer) Aquiferous unit file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 363 VES No. Location Coordinates Layer No. Resistivity(Ohm-m) Thickness (m) Inferred Layer Remark 3 1109.59 - Competent basement 9 Phase II (BH2) N 070 47’ 44.3” E 060 42’ 18.6” 1 1092.09 3.25 Topsoil (clay/laterite 2 50.44 12.51 Weathered basement(aquifer) Aquiferous unit 3 4432.72 - Competent basement 10 Otokiti Estate (BH) N 070 48’ 18.5” E 060 41’ 7” 1 25.92 2.86 Topsoil (clay/laterite 2 7.8 16.13 Weathered basement Aquiferous unit 3 330.45 - Competent basement 11 Army Barrack (BH) N 070 48’ 9.4” E060 40’ 34.5” 1 157.61 9.62 Topsoil (clay/laterite 2 55.61 12.54 Weathered basement(aquifer) Aquiferous unit 3 819.94 - Competent basement 12 Roja Table Water (BH 1) N 070 48’32.6” E060 38’41.3” 1 144.33 0.6 Topsoil (clay/laterite 2 8.48 3.39 Weathered basement(aquifer) Aquiferous unit 3 2875.1 - Competent basement 13 Zangodaji (BH 2) N 070 48’ 40.6” E 060 38’ 26.1” 1 58 6 Topsoil (clay/laterite 2 100.65 7 Clay/laterite 3 750.04 5 Weathered basement(aquifer) Aquiferous unit 4 1930.2 _ Competent basement 14 Adankolo (BH 1) N 070 47’ 15.6” E 060 44’ 16” 1 79.4 10 Topsoil (clay/laterite 2 99.35 4 Clay/laterite 3 317.5 3 Weathered basement(aquifer) Aquiferous unit 4 521.93 - Competent basement 15 Adankolo (BH 2) N 070 47’23.5” E060 44’ 28.6” 1 664 7.8 Topsoil (clay/laterite 2 66.84 8.8 Clay/laterite 3 316.62 5.7 Weathered basement(aquifer Aquiferous unit 4 505.53 - Competent basement 16 Adankolo (BH 3) N 070 47’ 21.6” E 060 44’ 17.5” 1 39.7 11.8 Topsoil (clay/laterite 2 79.86 6.14 Weathered basement(aquifer) Aquiferous unit 3 507.56 - Competent basement 17 Adankolo (BH 4) N 070 47’ 33.9” E 060 44’ 29.9” 1 372 15 Topsoil (clay/laterite 2 389.49 3.3 Clay/laterite 3 469.4 6.7 Weathered basement (aquifer) Aquiferous unit 4 690.3 Competent basement http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 364 VES No. Location Coordinates Layer No. Resistivity(Ohm-m) Thickness (m) Inferred Layer Remark 4 690.3 Competent basement 18 Marine Road (BH) N 070 48’ 7.1” E060 44’ 54.4” 1 79.4 10 Topsoil (clay/laterite) 2 198.2 13.5 Weathered basement(aquifer) Aquiferous unit 3 409.16 - Competent basement 19 Kenwo Hotel (HDW) N 070 47’ 50” E060 43’ 55.9” 1 99.35 7.5 Weathered basement 2 123 12.2 Weathered basement(aquifer) Aquiferous unit 3 1734.9 15.7 Fractured basement Aquiferous unit 4 678 - Competent basement 20 Kasuwa Hotel (BH) N 070 48’ 28.9” 1 317.5 3.7 Weathered/fractured basement E 060 44’ 55.5” 2 311.2 19 Weathered basement(aquifer) Aquiferous unit 3 1212.5 11.6 Fractured layer Aquiferous unit 4 1456 - Competent basement 21 GRAJ(GRA) (HDW) N 070 48’ 24.5” E 060 43’ 44.5” 1 521.93 4.6 Topsoil/clay/laterite 2 233.14 5.7 Weathered basement(aquifer) Aquiferous unit 3 895.8 - Competent basement 22 New Layout (HDW) N 070 48’ 37.8” E 060 44’ 12.7” 1 49.3 1.04 Topsoil (clay/laterite) 2 253.7 3.59 Clay/laterite 3 547.2 12.03 Weathered basement(aquifer) Aquiferous unit 4 780.2 - Competent basement 23 New Layout (HDW 2) N 070 48’ 37.2” E 060 44’ 32.8” 1 23 2.1 Topsoil (clay/laterite) 2 179.3 3.7 Clay/laterite 3 234.1 9.6 Weathered basement(aquifer) Aquiferous unit 4 1267.8 - Competent basement 24 Megiri (HDW ) N 070 48’ 45.1” E 060 44’ 42.1” 1 56.9 1.8 Topsoil (clay/laterite) 2 89.1 3.37 Clay/laterite 3 135.7 10.6 Weathered basement(aquifer) Aquiferous unit 4 230 - Competent basement 25 Kabawa (HDW) N 070 49’ 8.5” E060 44’ 54.7” 1 112.7 2.4 Topsoil (clay/laterite) 2 65.8 6.2 Clay/laterite 3 124.7 11.8 Weathered basement(aquifer) Aquiferous unit 4 569.2 Competent basement 26 SarkinNoma (HDW) N 070 50’ 31.3” E060 44’ 50” 1 354 7.01 Topsoil (clay/laterite) 2 213 13.09 Weathered basement(aquifer) Aquiferous unit 3 678 - Competent basement file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 365 VES No. Location Coordinates Layer No. Resistivity(Ohm-m) Thickness (m) Inferred Layer Remark 27 Felele (HDW 1) N 070 51’ 6.2” E060 43’ 31.7” 1 301 2.03 Topsoil (clay/laterite) 2 226.1 11.2 Weathered basement(aquifer) Aquiferous unit 3 429.5 - Competent basement 28 Felele (HDW 2) N 070 51’ 15.8” E 060 43’ 21.8” 1 29.4 5.6 Topsoil (clay/laterite) 2 79.5 9.17 Weathered basement (aquifer) Aquiferous unit 3 96.1 - Competent basement 29 Felele (HDW 3) N 070 51’ 6.6” E060 43’24.5” 1 45.8 3.6 Topsoil (clay/laterite) 2 67.23 13.6 Clay/laterite 3 156.9 7.9 Weathered basement(aquifer) Aquiferous unit 4 1273.1 - Competent basement 30 Behind Secretariat (HDW) N 070 45’ 47” E 060 43’ 32.8” 1 564.6 13 Tosoil 2 234.67 10.4 Clay/laterite 3 1472.4 12.4 Weathered basement (aquifer) Aquiferous unit 4 96.1 Competent basement 31 LGEA Primary school Zango 1 N 070 50’ 56” E060 45 34" 1 45.8 14.6 Topsoil (clay/laterite) 2 76.8 17.9 Weathered basement (aquifer) Aquiferous unit 3 1076 - Competent basement 32 LGEA Primary school Zango 2 N 070 48’ 37.2” E060 41’ 21” 1 18.8 12.8 Topsoil (clay/laterite 2 26.8 9.4 Weathered basement (aquifer) Aquiferous unit 3 79 - Competent basement 33 LGEA Primary school Zango 3 N 070 47’ 30.2” E060 44’ 32.8 1 29 8.9 Topsoil (clay/laterite 2 45 24.8 Weathered basement (aquifer) Aquiferous unit 3 86 - Competent basement 34 Mami Market N 070 46’ 41” E060 51’ 26” 1 41 9.4 Topsoil (clay/laterite 2 42 12.6 Weathered basement (aquifer) Aquiferous unit 3 53 - Competent basement 35 Model nurs. and prim. Sch. Aneibo quarters N 070 46’ 35” E 060 48’ 05” 1 123 5.7 Topsoil (clay/laterite 2 12 8.9 Weathered basement (aquifer) Aquiferous unit 3 201 - Competent basement http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 366 Table 2: Dar Zarrouuk Parameters The aquifer protective rating (Protection against contamination) of any aquifer can be established using Table 3 below (Oladapo and Akintorinwa, 2007). VES No. Location Layer resistivity(Rr w) Layer thickness (h) Aquifer conductivity (σ) Longitudinal conductance (s) Transverse resistance (R) Hydraulic conductivity (k) M/day Transmissivity (Tr)M2/day) 1 Ganaja BH1 17.87 10.83 0.05624296 0.60604364 193.53 26.24325 284.21 2 500 unit (BH1) 83.19 12.07 0.01202067 0.14508955 1076.53 6.250823 75.447 3 500 unit (BH2) 48.35 8.89 0.02068252 0.18386763 429.8 10.37 92.189 4 200 unit (BH1) 18.35 14.34 0.05449591 0.78147138 256.29 25.60232 367.137 5 200 Unit (BH2) 15.57 12.23 0.06422607 0.78548491 190.42 29.84245 364.973 6 Phase I (BH1) 277.6 3.7 0.0036023 0.01332853 1027.12 2.03115 7.5152 7 Phase I (BH2) 166.23 3.6 0.00601576 0.02165674 598.43 3.27712 11.797 8 Phase II (BH1) 6.81 3.61 0.14684287 0.5301028 24.5841 64.54349 233 9 Phase II (BH2) 50.44 12.51 0.01982553 0.24801744 631 9.96867 124.708 10 Otokiti Estate (BH) 7.8 16.13 0.12820512 2.06794872 125.81 56.86754 917.273 11 Army Barracks (BH) 55.61 12.54 0.01798237 0.22549901 697.35 9.10135 114.13 30 Behind Secretariat (HDW) 226.1 11.2 0.00442282 0.0495356 2531.3 2.45965 27.548 31 LGEA Primary school Zango 1 124.4 12.1 0.0080385 0.0923406 1505.24 2.60048 23.7623 32 LGEA Primary school Zango 2 167 8.9 0.005988 0.1287423 1504.1 1.48076 15.3225 33 LGEA Primary school Zango 3 76.9 13.3 0.0130039 0.2244317 1027.39 2.56871 34.3067 34 Mami Market 205.6 13.9 0.0048638 0.0872312 2796.16 3.24587 12.4326 35 Model nurs. and prim. Sch. Aneibo quarters 157.1 11.34 0.006365 0.11439123 1781.5 1.84089 69.0012 3.45855 27.3225 7290.15 6.52105 59.798 29 Felele (HDW 3) 156.9 7.9 0.00637349 0.05035054 1239.5 28 Felele (HDW 2) 79.5 9.17 0.01257862 0.11534591 27 Felele (HDW 1) 226.1 11.2 0.00442282 0.0495356 2531.3 2.45965 27.548 26 SarkinNoma (HDW) 213 13.08 0.00469483 0.06140845 2786.04 2.60048 34.0142 300.267 5.86317 19.7588 25 Kabawa (HDW) 124.7 11.8 0.00801924 0.0946271 1471.46 24 Megiri (HDW ) 89.1 3.37 0.00112233 0,0378227 4.28499 50.5628 23 New Layout (HDW 2) 234.1 9.6 0.00427168 0.0410081 2247.4 2.38115 22.859 22 New Layout (HDW) 547.2 12.03 0.00182749 0.0219846 6582.82 1.07848 12.9741 1328.9 2.3903 13.6247 21 GRAJ(GRA) (HDW) 198.2 13.5 0.00504541 0.068113 2675.7 20 Kasuwa Hotel (BH) 233.14 5.7 0.00428926 0.02444883 2.78118 37.5459 19 Kenwo Hotel (HDW) 1212.5 11.6 0.00082474 0.00956701 14065 0.51343 5.9557 18 Marine Road (BH) 1734.9 15.7 0.0005764 0.00904951 27237.9 0.36757 5.7708 490.34 6.49362 39.8708 17 Adankolo (BH 4) 469.4 6.7 0.00213937 0.01427354 3144.98 16 Adankolo (BH 3) 79.86 6.14 0.01252191 0.07688454 1.24434 8.337 15 Adankolo (BH 2) 316.62 5.7 0.00315836 0.01800379 1804.73 1.79663 10.24 14 Adankolo (BH 1) 317.5 3 0.0031496 0.00944882 952.5 1.79198 5.3759 28.75 52.60192 178.32 13 Zangodaji (BH 2) 750.04 10 0.00133326 0.01333262 7500 12 Roja Table Water (BH 1) 8.48 3.39 0.11792452 0.39976415 0.80365 8.0365 file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 367 Table 3: Rating of protective Capacity of Aquifers (After Oladapo and Akintorinwa, 2007). According to Offodile (1983), the aquifers in the study area were classified in terms of their yielding capacity using Transmissivity. This is as shown in Table 4. Table 4: Aquifer classification based on Transmissivity values (Offodile, 1983). Table 5 shows the protective capacity of the aquifers within study area obtained using their longitudinal conductance Longitudinal conductance (Ω—1) Protective capacity rating >10 Excellence 5–10 Very good 0.7–4.9 Good 0.2–0.69 Moderate 0.1–0.19 Weak 0.1 Poor Transmissivity (m 2 /day) Classification of well >500 High Potentials 50–500 Moderate Potential 5–50 Low Potential 0.5–5 Very low Potential <0.5 Negligible potential http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 368 Table 5: Longitudinal conductance and protective capacity of the study area Figure 3 is one of the geo-sections (station 16) obtained from the vertical electrical sounding carried out in the study area. It is one the station where three (3) geo-electric layers were encountered during the study. Protective capacity rating 30 Behind Secretariat (HDW) 0.0070633 Poor 31 LGEA Primary school Zango 1 0.09234012 Poor 32 LGEA Primary school Zango 2 0.1287434 Poor 33 LGEA Primary school Zango 3 0.2241145 Weak 34 Mami Market 0..087234 Poor 35 Model nurs. and prim. Sch. Aneibo quarters 0.1143912 Poor VES No. Locations Longitudinal conductance (s) 1 Ganaja BH1 0.60604364 4 200 unit (BH1) 0.78147138 Good 5 200 Unit (BH2) 0.78548491 Good Moderate 2 500 unit (BH1) 0.14508955 Weak 3 500 unit (BH2) 0.18386763 Weak 8 Phase II (BH1) 0.5301028 Moderate 9 Phase II (BH2) 0.24801744 Moderate 6 Phase I (BH1) 0.01332853 Poor 7 Phase I (BH2) 0.02165674 Poor 12 Roja Table Water (BH 1) 0.39976415 Moderate 13 Zangodaji (BH 2) 0.01333262 Poor 10 Otokiti Estate (BH) 2.06794872 Good 11 Army Barracks (BH) 0.22549901 Moderate 16 Adankolo (BH 3) 0.07688454 Poor 17 Adankolo (BH 4) 0.01427354 Poor 14 Adankolo (BH 1) 0.00944882 Poor 15 Adankolo (BH 2) 0.01800379 Poor 20 Kasuwa Hotel (BH) 0.02444883 Poor 21 GRAJ(GRA) (HDW) 0.068113 Poor 18 Marine Road (BH) 0.00904951 Poor 19 Kenwo Hotel (HDW) 0.00956701 Poor 24 Megiri (HDW ) 0,0378227 Poor 25 Kabawa (HDW) 0.0946271 Poor 22 New Layout (HDW) 0.0219846 Poor 23 New Layout (HDW 2) 0.0410081 Poor 28 Felele (HDW 2) 0.11534591 Poor 29 Felele (HDW 3) 0.05035054 Weak 26 SarkinNoma (HDW) 0.06140845 Poor 27 Felele (HDW 1) 0.0495356 Poor file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 369 Figure 3: Geo-electric section of station 16 in the study area. Table 6: Vertical Electrical Sounding Station 16 (3 layers) Depth(m) Thickness(m) Resistivity(ohm-m) Inferred lithology 0-11.8 11.8 39.70 Laterite 11.8-17.94 6.14 79.86 Weathered Basement >18 - 507.56 Basement Figure 4 is one of the geo-sections (station 17) obtained from the vertical electrical sounding carried out in the study area. It is one the station where four (4) geo-electric layers were encountered during the study. Figure 4: Geo-electric section of station 17 in the study area Weathered basement VES 16 0 11.8 17.9 Laterite Competent basement Weathered basement (Aquiferous unit) Competent basement VES 17 0 15 18.3 25 Laterite Clay http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 370 Table 7: Vertical Electrical Sounding Station 17 (4 layers) Depth (m) Thickness(m) Resistivity(ohm-m) Inferred lithology 0-15 15 372 Laterite 15-18.3 18.3 389.49 clay 18.3-25 >26 25 - 469.4 908.80 weathered Basement competent Basement Table 8 shows the hydraulic conductivity of the aquifers in the study area, obtained using the layer resistivity. file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 371 Table 8: Hydraulic conductivity of the aquifers in the study area VES No. Locations Hydraulic conductivity (k) M/day 1 Ganaja BH1 26.24325 2 500 unit (BH1) 6.250823 3 500 unit (BH2) 10.37 4 200 unit (BH1) 25.60232 5 200 Unit (BH2) 29.84245 6 Phase I (BH1) 2.03115 7 Phase I (BH2) 3.27712 8 Phase II (BH1) 64.54349 9 Phase II (BH2) 9.96867 10 Otokiti Estate (BH) 56.86754 30 Behind Secretariat (HDW) 0.42835 31 LGEA Primary school Zango 1 2.60048 32 LGEA Primary school Zango 2 1.48076 33 LGEA Primary school Zango 3 2.56871 34 Mami Market 3.24587 35 Model nurs. and prim. Sch. Aneibo quarters 1.84089 29 Felele (HDW 3) 3.45855 27 Felele (HDW 1) 2.45965 28 Felele (HDW 2) 6.52105 25 Kabawa (HDW) 4.28499 26 SarkinNoma (HDW) 2.60048 23 New Layout (HDW 2) 2.38115 24 Megiri (HDW ) 5.86317 21 GRAJ(GRA) (HDW) 2.78118 22 New Layout (HDW) 1.07848 19 Kenwo Hotel (HDW) 0.51343 20 Kasuwa Hotel (BH) 2.3903 17 Adankolo (BH 4) 1.24434 18 Marine Road (BH) 0.36757 15 Adankolo (BH 2) 1.79663 16 Adankolo (BH 3) 6.49362 13 Zangodaji (BH 2) 0.80365 14 Adankolo (BH 1) 1.79198 11 Army Barracks (BH) 9.10135 12 Roja Table Water (BH 1) 52.60192 http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 372 Table 9 shows the aquifer potential of the aquifers in the study area using transmissivity data obtained. Table 9: Aquifer potential of the aquifers in the study area 1 Ganaja BH1 Moderate 2 500 unit (BH1) Moderate 3 500 unit (BH2) Moderate 4 200 unit (BH1) Moderate 5 200 Unit (BH2) Moderate 6 Phase I (BH1) Very low 7 Phase I (BH2) Low 8 Phase II (BH1) Moderate 9 Phase II (BH2) Moderate 10 Otokiti Estate (BH) High 27.548 59.798 27.3225 30 Behind Secretariat (HDW) 4.4548 31 LGEA Primary school Zango 1 23.7623 32 LGEA Primary school Zango 2 15.3225 33 LGEA Primary school Zango 3 34.3067 34 Mami Market 12.4326 35 Model nurs. and prim. Sch. Aneibo quarters 69.0012 Low Low Low moderate Low Moderate Low Low Low 29 Felele (HDW 3) 27 Felele (HDW 1) 28 Felele (HDW 2) 25 Kabawa (HDW) 50.5628 moderate 26 SarkinNoma (HDW) 34.0142 Low 23 New Layout (HDW 2) 22.859 Low 24 Megiri (HDW ) 19.7588 Low 21 GRAJ(GRA) (HDW) 37.5459 Low 22 New Layout (HDW) 12.9741 Low 19 Kenwo Hotel (HDW) 5.9557 Low 20 Kasuwa Hotel (BH) 13.6247 Low 17 Adankolo (BH 4) 8.337 Low 18 Marine Road (BH) 5.7708 Low 15 Adankolo (BH 2) 10.24 Low 16 Adankolo (BH 3) 39.8708 Low 13 Zangodaji (BH 2) 8.0365 Low 14 Adankolo (BH 1) 5.3759 Low Moderate 12 Roja Table Water (BH 1) 178.32 Moderate 11.797 233 124.708 917.273 11 Army Barracks (BH) 114.13 284.21 75.447 92.189 367.137 364.973 7.5152 Ves No. Locations Transmissivity (Tr)M2/day) Aquifer potential file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 373 Figure 5. Map of the study area showing variation in Hydraulic Conductivity Figure 6. Map of the study area showing variation in Transmissivity Discussion From the result of the vertical electrical sounding (Table 1), two types of aquifer were delineated, namely; the weathered basement aquifer and weathered/fractured aquifer. The weathered basement aquifer was shown by VES 1 to 18, 21, 22 to 35 while weathered/fractured aquifer was revealed by VES stations 19 and 20. Thirteen (13) out of the thirty five (35) VES curves revealed a 4–layer geo-electric model (VES 6, 13 to 15, 17, 19, 20, 22 to 25, 29 &30) and the characteristic geo-electric signatures are AA- and HA- type curves, while the remaining twenty two (22) indicated a 3–layer geo-electric model and the characteristic geo-electric signatures are H- and A–type curves. The A – type curve represents a subsurface condition in which there is an increase in resistivity values from the topsoil to the bedrock (ρ1< ρ2< ρ3). The H – type curve represents a subsurface whereby the resistivity of the first layer is greater than the second layer while the resistivity of the second layer is less than the third layer (ρ1> ρ2< ρ3). The AA – type curve represents a subsurface which is composed of four layers in which there is an increase in resistivity from the first layer to the competent basement (ρ1< ρ2< ρ3< ρ4). The HA – type curve shows a subsurface in which the resistivity of the first layer is greater than the second layer while the second layer is less than the third layer and the resistivity of the third layer is less than the fourth layer (ρ1> ρ2< ρ3< ρ4). The topsoil generally comprises clay and laterite and constitutes the zone of aeration (phreatic zone). This zone contributes to groundwater development as it serves as a conduit through which meteoric water infiltrates the subsurface to form groundwater (Table 1). The weathered basement aquifer in the study area formed the second layer for the 3–layer formations. The depth of the layer ranges from 3.0m to 16.13m and the thickness ranges from 3.1m to 6.14m. The resistivity is of the range of 6.81Ωm to 166.23Ωm (Tables 1 and 2). For the four layer formations, the weathered layer aquifer forms the third layer. The depth of the layer varies from 18m to 25m, while the thickness ranges from 5m to 6.7m with a resistivity range of 316.62Ωm – 750.20Ωm. The groundwater yield of this aquifer type is determined by the degree of shaliness of the weathered zone. Low yield is encountered when the aquifer unit is clayey. This is because clay is not permeable to allow the flow of water. Sources of clay in Lokoja can http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 374 be attributed to weathering of feldspar of the Lokoja Formation and the Basement rocks in the area. The weathered/fractured aquifer forms the third layer in the four-layer geo-electric model. The depth of the layer ranges from 17m – 9.2m, a thickness range of between 3m and 3.7m and a resistivity varying from 277.6Ωm – 317.5Ωm (Table 1 and 2). This zone underlies the weathered zone directly. The groundwater yield from this aquifer type could be high if the density of the fractures in the fractured column is high. The fresh Basement Complex forms the last layer in the geo-electric section. The resistivity values of the competent basement for both aquifers vary from 33.45Ωm – 7724.31Ωm. The layer resistivity of the aquifers together with the thickness of the layer as shown in Table 2 were used to compute the various Dar Zarrouk parameters as shown in Table 2. The rating of the aquifer protective capacity according to Oladapo and Akintorinwa, 2007 is shown in Table 3. This rating was used as standard for the data obtained from the study area. The classification of aquifers based on their discharge ability/yielding ability according to Offodile, 1983 is shown in Table 4. This classification was used as standard for the data obtained from the study area. The longitudinal conductance was used to evaluate the protective capacity of the aquifers in the study according to Oladapo and Akintorinwa, 2007. The longitudinal conductance ranges from 0.00915ῼ to 2.063ῼ with an average of 1.068ῼ (Table 5). The results show that most of the aquifers in the area have poor to moderate protective capacity. This is an indication that most of the aquifers in the study area are adequately protected. Wells located in this area are therefore susceptible to surface contamination because of the proximity of the aquifer to the surface. Tables 6 and 7 show the geo-electric properties of some of the aquifers (Location 16 and 17). The results were obtained from vertical electrical sounding (VES) done with the aid of ABEM Terrameter using Schlumberger array. The hydraulic conductivity obtained ranges from 0.36757m/day to 56.86725m/day with a mean value of 21.34m/day (Table 8). The results show that the aquifers have low to moderate yielding potentials. The spatial distribution of hydraulic conductivity across the study area (Figure 4) that the southern part of the study has good yield that the northern area. The Transmissivity of the aquifer in the area ranges from 4.4543m2 to 912.273m2/day with a mean value of 213.34m2/day. This was used to compute the aquifer potential of the study area as shown in Table 9. The spatial distribution of Transmissivity across the study area shows poor to moderate potentials (Figure 5) The transverse resistance obtained ranges from 28.75ῼm2 to 7290ῼm2 with an average value of 1120 ῼm2 This result indicates very low groundwater development class (Ezeh, 2012). The spatial distribution as shown in Figure 6 indicate that the Northeastern part of the study have the least groundwater development. file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Omali and Arogundade: Geophysical Mapping of Aquifer Potential Zones Using Hydraulic Parameters in Lokoja and Environs, North- Central, Nigeria. AZOJETE, 18(3):345-376. ISSN 1596-2644; e-ISSN 2545-5818, www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 375 4. Conclusion The result of the vertical electrical sounding two types of aquifer was delineated, namely; the weathered basement aquifer and weathered/fractured aquifer. Thirteen (13) out of the thirty- five (35) VES curves revealed a 4–layer geo-electric model and the characteristic geo-electric signatures are AA- and HA- type curves, while the remaining twenty-two (22) indicated a 3– layer geo-electric model and the characteristic geo-electric signatures are H- and A–type curves. The results obtained revealed that the aquifers within the study area have poor to moderate protective capacity and very low to moderate yielding/discharge potentials. The resistivity soundings results revealed that about 4 curve types were identified in the study area namely AA, HA, A and H type with the lithologic layers varying from four 3 to 4 consisting of varying resistivity and thicknesses across each VES point. The geo-electric sections revealed that the major aquifer systems in the study area are weathered basement and weathered/fractured basement. The longitudinal conductance computed indicates that the aquifers in the area have poor to moderate protective capacity whereas transverse resistance indicates very low ground water development class. Hydraulic conductivity and transmissivity values indicate very low to moderate aquifer potentials. References Bello, R., Balogun, AO. and Nwosu, UM. 2019 Evaluation of Dar Zarrouk Parameters of Parts of Federal University of Petroleum Resources, Effurun, Nigeria. Journal of Applied Sciences and Environmental. Management, 23(9): 1709-1715. Billing, MP. 1972. Structural Geology. In: Eaglewood Cliffr. 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IOSR Journal of Applied Geology and Geophysics, 6(5): 29–37. Kwami, IA., Ishaku, JM., Bello, AM., Yusuf, A. and Mukkafa, S. 2019. Delineation of aquifer potential zones using hydraulic parameters in Gombe and environs, North-east Nigeria. Heliyon, 5(7): e01927. http://www.azojete.com.ng/ file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com Arid Zone Journal of Engineering, Technology and Environment, September, 2022; Vol. 18(3):357-376. ISSN 1596-2644; e-ISSN 2545- 5818; www.azojete.com.ng Corresponding author’s e-mail address: omaliaurelius@yahoo.com 376 Malick, SB., Bhattacharya, DC. and Nag, SK. 1973. Behaviour of fractures in hard rocks – a study by surface geology and radial VES methods. Geoexploration, 1: 529–556. Mbonu, DDC., Ebeniro, JO., Ofoegbu, CO. and Ekine, AS. 1991. 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Hydrogeophysical investigation for groundwater in Lokoja Metropolis, Kogi State, Central Nigeria. Journal of Geography and Geology, 6(1): 81-95. Stefanesco, SS., Schlumberger, C. and Schlumberger, M. 1930. Sur la distribution electrique potentielle autor d'une prix de terre ponctuelle dansun terrain a couche horizontales, homogenes et isotrope: Jour. Physique et le Radium, 11(1): 132–140. Todd, KD. 1980. Groundwater Hydrology, third ed. John Wiley and Sons, New York, pp. 636. Udoinyang, IE. and Igboekwe, MU. 2012. Aquifer Transmissivity, Dar Zarrouk Parameters and the Direction of Flow of suspended particulate Mattee in Boreholes in MOUAU and the Kwa Ibo River Umudike-Nigeria. Green Journal of Physical Science, 2(3): 70-78. Zohdy, AAR. 1989. A New method for the automatic interpretation of Schlumberger and Wenner sounding curve. Geophysics, 54: 245 – 253 file:///C:/user/Downloads/azojete143/www.azojete.com.ng file:///C:/Users/HP/Documents/Engr%20Oyeniyi/azojete/AZOJETE%20ARCHIVE/UPLOAD/VOL%2018%20NO%203/azojete18no_3firstbatchofpapers/omaliaurelius@yahoo.com