Browsing by Author "Ojulari, Bashiru Alaba"

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    Electrical Assessment of Aquifers in the Basement Complex of Unilorin: Implication for Existing Boreholes
    (Journal of Science, Technology, Mathematics and Education (JOSTMED), 2015-08-27) Ojulari, Bashiru Alaba; Saminu OLATUNJI
    Schlumberger 4-electrode array was employed to sound 21 stations. IPI2WIN and surfer12 softwares were used to infer lithological series, aquifer thickness and depth. The aquifer hydraulic conductivity K and transmissivity T were calculated from the VES data using the Dar Zarouk principles. The area shows 3 and 4 geo-electric layers from the computer iteration. The layers were interpreted as the topsoil (130- 1469 Ωm), clayey (wet to dry) (52.6- 8552 Ωm), weathered/fractured basement (46.2-249 Ωm) and fresh basement (454-5022 Ωm). The aquiferious zones lie within the second and third layers. The aquifer depth is between 6.17 m and 24.9 m while the thickness range is 1.89-22.7 m. The longitudinal conductance S ranges from 0.02 to 0.468 Ω-1and transmissivity T varies from 246 to 2419.8 Ωm2. The results conformed with the functional boreholes, such as at VES 3, sited in areas with thickest aquifers and highest transmissivity T. The NE and NW parts were found most suitable for fresh water exploitations. Low longitudinal conductance which implies low protective cover, in the vicinity of the borehole near VES6 confirmed the contamination claim of its water.
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    Geophysical, Geotechnical and Groundwater Quality Assessment of a Proposed Sanitary Landfill at Gosa Village, Abuja, Nigeria
    (Journal of Mining and Geology, 2017-08-27) Ige, O.O.; Ojulari, Bashiru Alaba
    Geophysical, geotechnical and water quality investigations of Gosa dumpsite in Abuja were carried out with a view to investigating the feasibility of upgrading it to a modern sanitary landfill. Nineteen Vertical Electrical Soundings (VES) were carried out for geoelectric characterization of the site. Also, eight soil samples (two undisturbed samples and six disturbed samples) were obtained for geotechnical analysis. Inversion of the VES data indicated 3 to 4 geoelectric layers namely; topsoil, laterite, weathered basement and fresh basement. Depth to basement varied from 4.1 m to 27.2 m. Geotechnically, the soil samples from the study area were classified as well graded clayey-sand to silty-sand. Plasticity of the clay fraction of the samples varied from low to intermediate. Maximum activity of clay (Ac) of 0.6 showed presence of inactive clay. Permeability test showed that the permeability of the sample ranges -7-6 between 5.1 x 10 m/s-1.1 x 10 m/s which makes the groundwater prone to leachate pollution.