Browsing by Author "Olatunji, S."

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    EVALUATION OF GROUNDWATER LEVEL TIME-DEPENDENT VARIATION AND AQUIFER CHARACTERISTICS WITHIN SHEET 223, ILORIN NORTH WEST, SOUT
    (COOU Journal of Physical Sciences, 2022) Ajadi, J.; Issa,U.; Olatunji, S.
    The assessment of groundwater level time-dependent variation and aquifer characteristics has been carried out, aimed at knowing the variation in groundwater elevation at the end of the rainy season and at the peak of the dry season. The time-dependent variation was done by direct in situ groundwater level measurement from eighty existing wells. Aquifer characteristics were determined by using pumping test data of the available boreholes in the area, using modified Jacob’s method. Configuration of groundwater level contours shows that the highest groundwater elevation in the area is 445 m and the lowest is 295 m above sea level. Also, areas with water levels ranging between 1 and 2 m are areas of low water level while areas with water levels ranging between 9.5 m and 11 m are areas of high water level. Transmissivity is estimated to range between 3.49 and 8.50 m 2 /day with an average value of 5.61 m2 /day, Hydraulic conductivity range between 2.18 × 10-1 and 7.64× 10-2 m /day with an average value of 1.65 × 10-1 m /day and Storativity range from 3.45 to 9.15 with an average value of 5.04. Areas with the shallow water level, depicting high potential, are in the southern part while the northern part is an area of low groundwater potential. The average value for Storativity is higher than the assigned limit (0.005-0.00005) for most confined aquifers, indicating that the storage potential of the boreholes is high; hence their recharge potential is high
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    GROUNDWATER POTENTIAL DELINEATION USING AEROMAGNETIC DATA WITHIN SHEET 223 ILORIN NW, SOUTH-WESTERN NIGERIA
    (Journal of Natural and Applied Sceiences, 2021-12) Issa, U.; Olatunji, S.; Ajadi, J.
    The aeromagnetic interpretation of the area was carried out to assess the groundwater potential of the area. This leads to getting information about the subsurface deeper source and the presence of lineaments equivalence of fractures. The aeromagnetic airborne data was used with the software Geosoft of Oasis Montaj v.6.4.2 using the convolution of Fourier transformation to obtain magnetic intensities of the area. The Total Magnetic Intensity (TMI) reveals three main types of magnetic anomalies ranging in intensity from -102.68 to 101.40 nTand classified into high, moderate, and low amplitude anomalies. The Regional Magnetic Intensity (RMI) ranges in magnitude from -18.55 to 82.35 nT, the residual magnetic field intensity ranges in intensity from - 35.87 to 35.74 nT, Reduction to the equator (RTE) residual magnetic field intensity exhibits values ranging from -99.3395 to 74.7526 nT and the tilt derivative anomalies range from -1.3624 to 1.3634 nT/m. The high magnetic anomalous areas are dominantly found in the fine-grained granite zone; indicating high groundwater potential. The regional structure of the area trends along the NW-SE direction, which conforms to the general structural trends existing in the Basement Complex of Nigeria.
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    Groundwater Potential Evaluation in Parts of Southwestern Nigeria Using Dar-Zarouk Parameters
    (LAUTECH Journal of Civil and Environmental Studies, 2022-03) Olatunji, S.; Issa, U.; Ajadi, J.
    Dar-Zarouk parameters namely longitudinal conductance, transverse unit resistance, longitudinal resistivity, traverse resistivity, and coefficient of anisotropy, derived from electrical resistivity soundings,were employed in the western and south western portions of Sheet 223 Ilorin NW, Southwestern Nigeria to evaluate the subsurface water prospect. This is aimed at determining the potentiality and vulnerability of groundwater in the area.The longitudinal conductance values obtained range from 0.027 S at VES 3 in the north, indicating the poorest protective capacity, to 26440.95 S at VES 157 in the south, indicating the highest protectivity. Thus, the protective capacity rating of the study area shows very poorly, weak, moderate, good, and excellent ratings at VES stations 10, 12, 9, 2, and 178 respectively.The total transverse resistance range is 8.6 - 32733.87 Ωm2 , with the lowest at VES 206 in the southeastern part, indicating high prospects, and the highest at VES 47 in the northern part of the area, indicating poor prospect.The lowest longitudinal resistivity (0.1951 Ωm), indicating high potential as well, occurs at the southern part and while the highest value of 8095.63 Ωm is obtained at the northern part.Furthermore, the coefficient of anisotropy in the area ranges between 0.029 and 5349.78. The south western boreholes have values that fall between the standard range of 1.39-1.66, indicating that those areas have boreholes with high productivity.In conclusion, most parts of the study area have excellent protective capacities and high potentiality.