Upscaling soil saturated hydraulic conductivity from pore throat characteristics

Ghanbarian, Behzad; Hunt, A. G.; Skaggs, Todd H.; Jarvis, Nicholas

doi:10.1016/j.advwatres.2017.03.016

Cited by 37 publications

(30 citation statements)

References 56 publications

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“…Katz and Thompson () also proposed a method to estimate d opt for individual samples from the accessible pore size distribution obtained from mercury intrusion experiments. In our study, we adopted a simpler approach to estimate d opt based on the assumption that for wide distributions of pore thickness, d opt can be estimated from [1 − ( t /(1 + t ))] d c where t is a critical exponent from percolation theory, which equals 2 in three dimensions (Ghanbarian et al, ; Katz & Thompson, ; Stauffer & Aharony, ). Thus, in this study, ϕ eff is given by one third of ϕ p , where ϕ p is the accessible and percolating porosity corresponding to pores thicker than d c /3.…”

Section: Methodsmentioning

confidence: 99%

“…Water Resources Research recent study by Ghanbarian et al (2017) compared K s estimates derived from a fractal CPA model with average measured values for U.S. Department of Agriculture soil texture classes, but this model was not tested against data for individual soil samples. Furthermore, the model parameters were estimated indirectly.…”

Section: 1029/2018wr023609mentioning

confidence: 99%

“…Percolation and CPA‐based approaches have been successfully applied to predict the permeability of rocks and artificial porous materials such as ceramics and concrete (Arns et al, ; Ghanbarian et al, ; Katz & Thompson, ; Nishiyama & Yokoyama, , ; Nokken & Hooton, ), but they have not yet been critically tested on soils. A recent study by Ghanbarian et al () compared K s estimates derived from a fractal CPA model with average measured values for U.S. Department of Agriculture soil texture classes, but this model was not tested against data for individual soil samples. Furthermore, the model parameters were estimated indirectly.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X‐Ray

Koestel

Dathe

Skaggs

et al. 2018

Water Resources Research

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The saturated hydraulic conductivity of soil, Ks, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate Ks measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, dc, and the effective porosity) were derived from X‐ray computed tomography measurements. The model gave a highly significant fit to the Ks measurements (p < 0.0001) although only ~47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of Ks. Variation in the critical pore diameter, dc, was the dominant source of variation in Ks, which suggests that dc is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of dc with basic soil properties and site attributes.

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Section: Methodsmentioning

confidence: 99%

Section: 1029/2018wr023609mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X‐Ray

Koestel

Dathe

Skaggs

et al. 2018

Water Resources Research

Self Cite

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“…Because recent PTFs are now able to estimate relatively well the scale, α, and shape, n, parameters featuring van Genuchten's WRF, it has been recognized that a research challenge would be to reduce the uncertainty in estimating parameter K s as much as possible. Interesting approaches to the latter issue are reported in some recent papers [41][42][43].…”

Section: Simplified Estimation Of the Soil Hydraulic Characteristics mentioning

confidence: 99%

Intertwining Observations and Predictions in Vadose Zone Hydrology: A Review of Selected Studies

Romano

2020

Water

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Observing state variables, fluxes, and key properties in terrestrial ecosystems should not be seen as disjointed, but rather as fruitfully complementary to ecosystem dynamics modeling. This intertwined view should also take the organization of the monitoring equipment into due account. This review paper explores the value of the interplay between observations and predictions by presenting and discussing some selected studies dealing with vadose zone hydrology. I argue for an advanced vision in carrying out these two tasks to tackle the issues of ecosystem services and general environmental challenges more effectively. There is a recognized need to set up networks of critical zone observatories in which strategies are developed and tested that combine different measurement techniques with the use of models of different complexity.

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“…These different fractal dimensions can be used to characterize the geometry of a porous medium in relation to transport processes (Ghanbarian et al, ; Yang et al, ; Zhang et al, ). Data to compute fractal dimensions can be obtained from various techniques, for example, 2‐D optical microscopy or 3‐D fluid intrusion data such as N 2 or CO 2 low‐pressure sorption, or from nondestructive particle‐scanning methods, such as small‐angle scattering using neutrons or X‐rays.…”

Section: Introductionmentioning

confidence: 99%

Predicting Effective Diffusion Coefficients in Mudrocks Using a Fractal Model and Small‐Angle Neutron Scattering Measurements

Busch

Kampman

Bertier

et al. 2018

Water Resources Research

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The determination of effective diffusion coefficients of gases or solutes in the water‐saturated pore space of mudrocks is time consuming and technically challenging. Yet reliable values of effective diffusion coefficients are important to predict migration of hydrocarbon gases in unconventional reservoirs, dissipation of (explosive) gases through clay barriers in radioactive waste repositories, mineral alteration of seals to geological CO2 storage reservoirs, and contaminant migration through aquitards. In this study, small‐angle and very small angle neutron scattering techniques have been utilized to determine a range of transport properties in mudrocks, including porosity, pore size distributions, and surface and volume fractal dimensions of pores and grains, from which diffusive transport parameters can be estimated. Using a fractal model derived from Archie's law, we calculate effective diffusion coefficients from these parameters and compare them to laboratory‐derived effective diffusion coefficients for CO2, H2, CH4, and HTO on either the same or related mudrock samples. The samples include Opalinus Shale from the underground laboratory in Mont Terri, Switzerland, Boom Clay from a core drilled in Mol, Belgium, and a marine claystone cored in Utah, USA. The predicted values were compared to laboratory diffusion measurements. The measured and modeled diffusion coefficients show good agreement, differing generally by less than factor 5. Neutron or X‐ray scattering analysis is therefore proposed as a novel method for fast, accurate estimation of effective diffusion coefficients in mudrocks, together with simultaneous measurement of multiple transport parameters including porosity, pore size distributions, and surface areas, important for (reactive) transport modeling.

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Upscaling soil saturated hydraulic conductivity from pore throat characteristics

Cited by 37 publications

References 56 publications

Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X‐Ray

Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X‐Ray

Intertwining Observations and Predictions in Vadose Zone Hydrology: A Review of Selected Studies

Predicting Effective Diffusion Coefficients in Mudrocks Using a Fractal Model and Small‐Angle Neutron Scattering Measurements

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