College of Physical Sciences

Permanent URI for this collectionhttps://ir.funaab.edu.ng/handle/123456789/256

Browse

Browsing College of Physical Sciences by Author "OLADODU IYANUOLUWAOLUWATOBILOBA"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    CHARACTERIZATION OF AQUIFER FOR WATER SUPPLY TO CULTIVATED FARMLAND IN A BASEMENT COMPLEX USING ELECTRICAL RESISTIVITY METHOD ON DUFARMS AT FEDERAL UNIVERSITY OF AGRTICULTURE ABEOKUTA NIGERIA
    (2025-06-23) OLADODU IYANUOLUWAOLUWATOBILOBA
    ABSTRACT This study aims to characterize aquifer systems within a crystalline Basement Complex terrain to enhance groundwater supply for cultivated farmland, using the 1D Electrical Resistivity Method. The investigation was conducted at DUFARMS ASSETRISE LIMITED FARM, located within the Federal University of Agriculture, Abeokuta (FUNAAB), Ogun State, Nigeria, where agriculture is critically dependent on groundwater due to irregular and seasonal rainfall patterns. The geophysical technique adopted was Vertical Electrical Sounding (VES) using the Schlumberger electrode configuration. A total of 24 VES points were surveyed across different sections of the farmland to assess the subsurface lithology and aquifer potential. Field data were processed and interpreted using IP2WIN and WinResist software packages, generating one-dimensional resistivity models for each sounding point. The interpretation revealed a stratified subsurface composed of topsoil, weathered basement, fractured basement zones, and fresh basement rock. The topsoil layer showed resistivity values ranging from 48 to 320 Ω•m, with an average thickness of 0.6 to 2.2 meters, indicating variations in soil composition (sandy, lateritic, or loamy) across the site. Beneath this layer, the weathered basement exhibited resistivity values between 20 and 90 Ω•m, with thicknesses ranging from 3.5 to 15.6 meters—a zone often saturated and serving as a primary aquifer unit. In some locations, fractured basement zones were identified with moderately low resistivity values (typically less than 60 Ω•m), indicating secondary porosity and groundwater storage potential. The dominant curve types encountered include H-type, KH-type, HA-type, and QH-type curves. The H and KH types were most prevalent, indicating a common geoelectric sequence of a relatively resistive topsoil underlain by a more conductive weathered or saturated zone, followed by a resistive fresh basement. These curve types are diagnostic of aquifer-bearing formations within basement terrains. The study identifies the second and third geoelectric layers—corresponding to the weathered and fractured basement zones—as the principal aquiferous units. These layers are potential targets for hand-dug wells, boreholes, or small-scale irrigation schemes. In conclusion, the 1D resistivity method has proven to be a reliable, non-invasive, and cost-effective approach for delineating groundwater-bearing formations in crystalline basement settings. The findings offer valuable guidance for irrigation planning, sustainable water resource management, and borehole siting on the DUFARMS farmland and similar agricultural projects in southwestern Nigeria.
  • No Thumbnail Available
    Item
    CHARACTERIZATION OF AQUIFER FOR WATER SUPPLY TO CULTIVATED FARMLAND IN A BASEMENT COMPLEX USING ELECTRICAL RESISTIVITY METHOD ON DUFARMS AT FEDERAL UNIVERSITY OF AGRTICULTURE ABEOKUTA NIGERIA
    (2025-06-25) OLADODU IYANUOLUWAOLUWATOBILOBA
    ABSTRACT This study aims to characterize aquifer systems within a crystalline Basement Complex terrain to enhance groundwater supply for cultivated farmland, using the 1D Electrical Resistivity Method. The investigation was conducted at DUFARMS ASSETRISE LIMITED FARM, located within the Federal University of Agriculture, Abeokuta (FUNAAB), Ogun State, Nigeria, where agriculture is critically dependent on groundwater due to irregular and seasonal rainfall patterns. The geophysical technique adopted was Vertical Electrical Sounding (VES) using the Schlumberger electrode configuration. A total of 24 VES points were surveyed across different sections of the farmland to assess the subsurface lithology and aquifer potential. Field data were processed and interpreted using IP2WIN and WinResist software packages, generating one-dimensional resistivity models for each sounding point. The interpretation revealed a stratified subsurface composed of topsoil, weathered basement, fractured basement zones, and fresh basement rock. The topsoil layer showed resistivity values ranging from 48 to 320 Ω•m, with an average thickness of 0.6 to 2.2 meters, indicating variations in soil composition (sandy, lateritic, or loamy) across the site. Beneath this layer, the weathered basement exhibited resistivity values between 20 and 90 Ω•m, with thicknesses ranging from 3.5 to 15.6 meters—a zone often saturated and serving as a primary aquifer unit. In some locations, fractured basement zones were identified with moderately low resistivity values (typically less than 60 Ω•m), indicating secondary porosity and groundwater storage potential. The dominant curve types encountered include H-type, KH-type, HA-type, and QH-type curves. The H and KH types were most prevalent, indicating a common geoelectric sequence of a relatively resistive topsoil underlain by a more conductive weathered or saturated zone, followed by a resistive fresh basement. These curve types are diagnostic of aquifer-bearing formations within basement terrains. The study identifies the second and third geoelectric layers—corresponding to the weathered and fractured basement zones—as the principal aquiferous units. These layers are potential targets for hand-dug wells, boreholes, or small-scale irrigation schemes. In conclusion, the 1D resistivity method has proven to be a reliable, non-invasive, and cost-effective approach for delineating groundwater-bearing formations in crystalline basement settings. The findings offer valuable guidance for irrigation planning, sustainable water resource management, and borehole siting on the DUFARMS farmland and similar agricultural projects in southwestern Nigeria.