Over 400 unlithified sediment samples were collected from four different depositional environments in global locations and the grain-size distribution, porosity, and hydraulic conductivity were measured using standard methods. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations (e.g., Hazen, Carman-Kozeny) commonly used to estimate hydraulic conductivity from grain-size distribution. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values with errors ranging to over 500%. To improve the empirical estimation methodology, the samples were grouped by depositional environment and subdivided into subgroups based on lithology and mud percentage. The empirical methods were then analyzed to assess which methods best estimated the measured values. Modifications of the empirical equations, including changes to special coefficients and addition of offsets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, offshore marine, and river sediments. Estimated hydraulic conductivity errors were reduced to 6 to 7.1m/day for the beach subgroups, 3.4 to 7.1m/day for dune subgroups, and 2.2 to 11m/day for offshore sediments subgroups. Improvements were made for river environments, but still produced high errors between 13 and 23m/day. © 2013, National Ground Water Association.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was funded by the Desalination and Water Reuse Center at King Abdullah University of Science and Technology and from discretionary research funding provided by the university. Mr. Samir Al-Mashhawari conducted the field operations and coordinated sediment sampling along the Red Sea and Arabian Gulf shorelines, in the wadi systems, and dune fields in Saudi Arabia. Khan Jadoon reviewed the full manuscript before final submittal. We thank Drs. Y.-K. Zhang, D. Boult, and J. Levy for detailed peer reviews of the paper that considerably improved its content and quality.
ASJC Scopus subject areas
- Water Science and Technology
- Computers in Earth Sciences