Estimation of porosity and hydraulic conductivity of shallow Quaternary Alluvial Aquifer in Yenagoa, Southern Nigeria, using geoelectrical measurements

Abstract

In this study, two theoretical methods based respectively on Archie-Kozeny equations and Ohm's-Darcy's laws were used to determine porosity and hydraulic conductivity of shallow aquifer in Yenagoa, Southern Nigeria. Fourteen Vertical Electrical Soundings (VES) using the Schlumberger configuration were carried out within the Quaternary Alluvial deposit with maximum electrode spacing (AB/2) of 200 m. The calculated apparent resistivity data were inverted using the Interpex 1×1D computer software. The results indicated that the porosity (ϕ) and hydraulic conductivity values in the aquifer varied from 0.08 – 0.29 and 1.14 × 10^-4 - 87.4 × 10^-4 m/s respectively. Correlation of estimated hydraulic conductivity values from the VES data and those conventionally determined by pump test showed a fairly good correlation.

Keywords: Hydraulic Conductivity, Porosity, Formation Factor, Geoelectric Sounding, Yenagoa, Niger Delta
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