Browsing by Author "Olelewe, M. C.,"

Now showing 1 - 2 of 2
  • Item
    Hydro-sedimentological Evaluation of Aquifer Properties In Parts of Southern Anambra Basin.
    (Faculty of Applied Sciences, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria., 2025) Iheme, K. O.,; Obaro, R. I.,; Abubakar, H. O.,; Omotoso, O. A.,; Ibrahim, K. O.,; Olelewe, M. C.,; Magbo, J. C.
    Nigeria's cities lack potable water supply system, due to failed water supply system, leading to groundwater reliance. Understanding hydrogeological settings of some basins like Anambra Basin is tough due to its complex geological heterogeneity and varying sedimentary structures. The commonly used electrical resistivity method has ambiguity issues because it often struggles to distinguish between different lithological units with similar resistivity values, leading to misinterpretation of subsurface geology. The alternative hydro-sedimentological approach estimates aquifer properties from grain size. In this study, twenty-five (25) sand samples were collected from boreholes cuttings; this is because sands are the primary aquifer-hosting materials in southern Anambra Basin. Ten empirical relationships were used to estimate hydraulic conductivities from the grain size data. Porosity, specific yield (SY), and specific retention (SR) were also empirically determined. Pumping data were available for ten (10) locations. For the remaining fifteen (15) locations, where pumping tests were not conducted, permeameter tests were performed on well cuttings to estimate hydraulic conductivity. The graphic mean of the sands ranges from 0.071 to 1.533phi, indicating that the sands are mainly medium-sized. Fractional porosity values, Specific yield and Specific retention range from 0.260 to 0.392, 0.274 to 0.039, and 0.125 to 0.322, respectively. Hydraulic conductivity ranges estimated from Hazen Simplified, Slichter, Terzaghi, Beyer, Sauerbrei, USBR, Barr, Alyamani & Sen, Chapuis, and Uma models are between 1.31-22.37m/day, 0.31-6.85m/day, 0.5-12m/day, 1.4-19m/day, 1.22- 16.71m/day, 1.42-13.37m/day, 0.36-9.3m/day, 0.01-8.72m/day, 0.17-11.3m/day, and 0.02- 10.64m/day respectively. Hydraulic conductivity obtained from pumping test ranges from 0.89 to 7.06m/day, while the values are 0.0864 to 25.488m/day from permeameter test, classifying the aquifers as having medium to high groundwater potential according to Terzaghi, Barr, Chapius and Uma estimates. In conclusion, this study was able to map out the groundwater potential of the area and revealed the most suitable empirical relation for estimating groundwater potentials within the area.
  • Item
    HYDROCHEMICAL APPRAISAL OF GROUNDWATER RESOURCES IN PART OF SOUTHERN ANAMBRA BASIN: ITS IMPLICATIONS FOR IRRIGATION PURPOSE
    (Faculty of Applied Sciences, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria., 2025) Iheme, K. O.,; Usman, A. O.,; Abubakar, H. O.,; Magbo, J. C.,; Yusuf, M. A.,; Olelewe, M. C.,; Ohanele, E. C.
    Irrigation is vital for food security, but climate change and pollution threaten it. Thus, regular evaluations of groundwater quality for irrigation are needed. This study collected and analyzed thirty-five (35) groundwater samples from boreholes in the Southern Anambra Basin, covering the Ameki and Ogwashi-Asaba Formations. Six irrigation quality indices: Kelly’s Ratio (KR), Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP), Residual Sodium Carbonate (RSC), Magnesium Adsorption Ratio (MAR), and Permeability Index (PI), were calculated to evaluate the area’s irrigation suitability. Doneen PI, USSL, and Wilcox diagrams were also employed in evaluating irrigation suitability. The pH, EC, and TDS of the groundwater samples ranged from 6.6 to 8.4, 13 to 889μS/cm, and 15.6 to 557.9mg/L, respectively. The concentrations of HCO3-, SO42-, Cl-, Ca2+, Mg2+, Na+, and K+ ranged from 24 to 580, 1 to 20, 0.4 to 92.5, 10 to 74, 0.09 to 49.50, 2.26 to 30, and 0.67 to 10.0 mg/L, respectively. In general, the physicochemical parameters met the WHO and NSDWQ guidelines for drinking waters. The range of KR, SAR, SSP, RSC, MAR, and PI were 0.019-1.712mmol/L, 0.067-2.113, 1.86-63.13%, -5.36-7.80mmol/L, 0.00-3.79, and 15.82-547.10%, respectively. All samples had suitable SAR and MAR values for irrigation, while 97.14%, 94.29%, 80%, and 77.14% had suitable SSP, KR, RSC, and PI, respectively. This study has demonstrated that groundwater within the study area is suitable for drinking and irrigation, however, it is essential for periodic assessment as anthropogenic activities continue to increase in the area.