Determination of Aquifer Hydraulic and Statistical Parameters Using Granulometric Method in Yenagoa, Southern Nigeria

Grain-size analysis of aquifer sand samples from Yenagoa was carried out by the mechanical sieving technique. Using the grain-size analysis curves, mean representative grain diameters d10 and d60 were determined and porosity was derived from the empirical relationship between porosity and grain uniformity (η). From determined porosity values, hydraulic conductivity was computed using Kozeny-Carman and Hazen equations. The result showed that porosity ranged between 0.41 - 0.45, while the hydraulic conductivity (k) values ranged from 8x10-4 m/s to 4x10-3 m/s and 6x10-4 m/s to 4x10-3 m/s respectively in the area. The high porosity and hydraulic conductivity values were consistent with aquifer characteristics of unconsolidated fine to medium coarse coastal sands.