Evaluation of empirical formulae for the determination of hydraulic conductivity based on grain-size analysis

Several empirical formulae were used to determine the hydraulic conductivity of aquifer materials in the Jimeta-Yola area. The results indicate that the best estimation of hydraulic conductivity is based on Terzaghi equation, followed by Kozeny-Carman, Hazen, Breyer and Slitcher equations, respectively. The mean values from these equations were 1508, 287.1, 213.3, 186.9 and 102.3 m/day. The estimated hydraulic conductivities from the different methods indicate the hydraulic conductivity of clean sand to gravelly materials. USBR method underestimated the hydraulic conductivity of the aquifer materials in the area. The method, indicate the hydraulic conductivity of fine sand.   Key words: Hydraulic conductivity, aquifer, empirical formulae, Bima Sandstone, sieve analysis.