Resumo

; ROMANS, Anna M.  e  BUTTURINI, Andrea. Estimating the hydraulic conductivity in river unconsolidated sediments. A critical analysis of several grain-size empirical approaches. Ser. correl. geol. [online]. 2022, vol.38, n.1, pp.11-20. ISSN 1666-9479.  http://dx.doi.org/10.5281/zenodo.7194569.

Sediment hydraulic conductivity (K) is an essential to understand subsuperficial flow in fluvial hypor-heic systems, and to study solute transport in those systems. In unconsolidated porous media, sediment grain-size distribution is an essential variable to estimate K. In this study, we explored the limits and applications of 11 defined formulas to empirically compute K values. For this purpose, 36 sand sediment corers of up to 60 cm depth were collected at the downstream reach of the Tordera River (located at the north-east of the Iberian Pe -ninsula) during three sampling campaigns (i.e., December 2012, June and July 2013). For our studied sediments (uniformly graded, moderately and poorly sorted), the Slichter, USBR and Harleman formulas gave the lowest K values while the Beyer and Terzaghi formulas the highest. On the other hand, our sample characteristics did not fit the applicability domain of the formulas defined by Krumbein and Monk, and Alyamani and §en (1993). However, two empirical formulas (Kozeny-Carman and Sauerbrei) yielded the K values closer to our first observed results (by in situ infiltration measurements), and within the K limits given by previous authors for the similar type of sediments. Therefore, our results obtained from a set of sand sediment samples suggest selecting the formula proposed by Kozeny-Carman to determine K from grain-size distribution in unconsolidated river sediments.

Palavras-chave : particle-size distribution; Kozeny-Carman equation; permeability; sandy sediment.

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