Empirical Methods and Estimation of Hydraulic Conductivity of Fluvial Aquifers

Abstract

The present work evaluates a few established empirical equations that calculate the hydraulic conductivity ( K ) of aquifer materials using grain size parameters. Loose sand samples (N = 51) of unconsolidated fluvial deposits, obtained from various aquifer zones in boreholes (N = 4), were used for the purpose. Grain size analyses of the samples were carried out through dry sieving, and different particle size parameters were determined from the size grading curves. The K values were estimated using the empirical equations. The applicability of the methods were assessed by estimating the K of fine to very coarse sand. To appraise the suitability of the methods, the K values were compared with those estimated through conducting pumping tests in the tube wells. The Breyer, Hazen, Terzaghi, and United States Bureau of Reclamation methods maintain consistency in estimating the K values of the fluvial sand with respect to the grain sizes. The Kozeny-Carman method yields moderately underestimated values of K for medium-coarse to very coarse sand. Slitcher and Terzaghi methods often underestimate the K values. While the Alyamani and Sen (A&S) method calculates the K within range for sand populations with U c U c > 5.