Department Of Geosciences

Permanent URI for this community

https://ir.unilag.edu.ng/handle/123456789/3384
The programmes are designed to train and produce graduates in the field of geology and geophysics that meet scientific and professional needs, necessary manpower requirements to the academic, research and governmental organizations, industry and other related areas. High priority is also given to teaching and research in the application of geological and geophysical techniques for natural resources development and solution to environmental challenges.

Browse

Browsing Department Of Geosciences by Subject "aquifers"

Now showing 1 - 2 of 2
  • Item
    Open Access
    Geoelectrical investigation of the groundwater potential in Mowe, Ogun State, Nigeria
    (British Journal of Applied Science & Technology, 2012) Adeoti, L; Alile, O.M O. M; Uchegbulam, O; Adegbola, R.B
    Electrical resistivity survey was carried out to delineate subsurface layers and to determine the ground water potential in the study area. The study was carried out using the ABEM SAS 1000 terrameter which worked on 16 vertical electrical sounding (VES) points within the area. A maximum distance of 550m current electrode spread was adopted for this survey. The result showed the presence of four geoelectric layers with the resistivity of the first layer ranging from 25.54Ωm to 619.45Ωm and thickness of 0.14-9.21m representing topsoil. The second geoelectric layer has resistivity ranging from 20.94Ωm to 706.82Ωm and thickness of 2.58 to 35.36m representing laterite. The third geoelectric layer has resistivity ranging from 12.29Ωm to 598.93Ωm and thickness of 3.33 to 58.06m representing sandy clay. The fourth geoelectric layer has resistivity ranging from 12.1Ωm to 1980.52Ωm and thickness of 11.4 to 45m representing sand. The depth to the aquifers are 13.11m, 55.31m, 6.35m, 50.28m, 51.08m and 28.01m in VES 1, 2, 6, 9, 11 and 16 respectively.
  • Item
    Open Access
    Geophysical investigation of saline water intrusion into freshwater aquifers: A case study of Oniru, Lagos State
    (Scientific Research and Essays, 2010) Adeoti, L; Alile, O.M; Uchegbulam, O
    A total of five electrical imaging lines were measured using the wenner configuration. And a total of twelve VES was carried out within the area of investigation. The lines were aligned almost in a linearly NS azimuths, perpendicular to the ocean. The results were presented as profiles, multi-profiles, maps, pseudo sections and inverted sections. Interpretations of these results involve both qualitative and quantitative deductions from 1D and 2D geoelectric models. WingLink software was utilized for plotting, filtering, modeling and iterations of the resistivity data. From the quantitative interpretation and nearby well log data five distinct layers were identified. The layers are dry and unconsolidated sand, clayey sand, saline sand, saline clay and freshwater sand. The resistivity of the topsoil varies from 3259.59 Ohm-m on VES 2 - 67.04 Ohm-m on VES 12. The resistivity of the freshwater sand varies from 1649.76 Ohm-m on VES 6 - 158.28 Ohm-m on VES 10. The resistivity of the saline layer (saline sand/clay) varies from 2.06 Ohm-m on VES 12 - 39.88 Ohm-m on VES 3. The depth to saline/freshwater interface varies from 12.97 m on VES 8 - 63.01 m on VES 5. The quality of groundwater varies from poor polluted saline water saturated sand/clay through intermediate water quality clayey sand/sand to freshwater sand. The interpreted results show saline water plumes where they occur in different part of the area investigated. The 1D and 2D results correlate to a very high degree indicating saline water intrusion between depth interval of 13 and 64 m in the study area. Two major freshwater aquifers (shallow < 6 m and deep > 60 m) where delineated with most of them occurring unprotected. The results showed the effectiveness and usefulness of electrical resistivity and induced polarization method in mapping saline water intrusion problem in coastal areas.