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You searched for: Subject "unsaturated flow" Remove constraint Subject: "unsaturated flow" Journal name Vadose zone journal Remove constraint Journal name: Vadose zone journal Subject term soil pore system Remove constraint Subject term: soil pore system
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1. The active fracture model: its relation to fractal flow patterns and an evaluation using field observations

Author:
Liu, H.H.; Zhang, G.; Bodvarsson, G.S.
Source:
Vadose zone journal 2003 v.2 no.2 pp. -
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; vadose zone; soil transport processes; mathematical models; soil pore system; Nevada;     Show all 6 Subjects
Abstract:
... The active fracture model (AFM) (Liu et al., 1998) has been widely used in modeling flow and transport in the unsaturated zone of Yucca Mountain, Nevada, a proposed repository of high-level nuclear wastes. This study presents an in-depth evaluation of the AFM, based on both theoretical arguments and field observations. We first argue that flow patterns observed from different unsaturated systems ( ...

2. A modeling study of flow diversion and focusing in unsaturated fractured rocks

Author:
Pan, L.; Wu, Y.S.; Zhang, K.
Source:
Vadose zone journal 2004 v.3 no.1 pp. -
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; simulation models; waste disposal; radionuclides; soil pore system; rocks; hazardous waste; porous media; soil transport processes; vadose zone; Nevada;     Show all 11 Subjects
Abstract:
... This study presents a systematic approach to analyze the flow diversion and flow focusing caused by the natural flow-barrier system in the unsaturated zone (UZ) of Yucca Mountain, Nevada, under ambient steady-state flow conditions. An existing analytical solution for analyzing capillary barrier in porous media has been extended to apply to the fractured porous rock. The new analytical solutions ar ...

3. Colloid mobilization and transport in undisturbed soil columns. I. Pore structure characterization and tritium transport

Author:
Kjaergaard, C.; Poulsen, T.G.; Moldrup, P.; Jonge, L.W. de
Source:
Vadose zone journal 2004 v.3 no.2 pp. -
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; simulation models; clay fraction; soil pollution; soil pore system; soil colloids; unsaturated conditions; porosity; pollutants; soil matric potential; soil transport processes; tritium; vadose zone; Denmark;     Show all 14 Subjects
Abstract:
... While it is recognized that preferential flow may increase the transport of colloids, less is known about the actual influence of preferential flow on colloid mobilization in situ. Changes in pore structure upon soil exposure to drying and rewetting may additionally affect colloid mobilization. Information about the pore structure and the active flow volume, as well as the changes in these propert ...

4. The relative connectivity-tortuosity tensor for conduction of water in anisotropic unsaturated soils

Author:
Raats, P.A.C.; Zhang, Z.F.; Ward, A.L.; Gee, G.W.
Source:
Vadose zone journal 2004 v.3 no.4 pp. -
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; soil pore system; unsaturated hydraulic conductivity; unsaturated conditions; equations; vadose zone; soil water movement;     Show all 7 Subjects
Abstract:
... The hydraulic conductivity of unsaturated anisotropic soils has recently been described with a tensorial connectivity-tortuosity (TCT) concept. We present a mathematical formalization of the connectivity-tortuosity tensor, assuming that its principal axes coincide with those of the hydraulic conductivity tensor at saturation. The hydraulic conductivity tensor of such unsaturated anisotropic soils ...

5. Simulation of unsaturated flow in complex fractures using smoothed particle hydrodynamics

Author:
Tartakovsky, A.M.; Meakin, P.
Source:
Vadose zone journal 2005 v.4 no.3 pp. -
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; simulation models; soil pore system; equations; soil water movement; vadose zone; hydrologic models;     Show all 7 Subjects
Abstract:
... Smoothed particle hydrodynamics (SPH) models were used to simulate unsaturated flow in fractures with complex geometries. The SPH is a fully Lagrangian particle-based method that allows the dynamics of interfaces separating fluids to be modeled without employing complex front tracking schemes. In SPH simulations, the fluid density field is represented by a superposition of weighting functions cent ...

6. Colloid Mobilization from a Variably Saturated, Intact Soil Core

Author:
Janna M. Levin; Janet S. Herman; George M. Hornberger; James E. Saiers
Source:
Vadose zone journal 2006 v.5 no.2 pp. 564-569
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; soil colloids; soil transport processes; unsaturated conditions; soil pore system; diffusion; infiltration (hydrology);     Show all 7 Subjects
Abstract:
... Colloids may transport contaminants through unsaturated soils to the groundwater, and colloid mobilization is associated with transient hydrological events and sustained, steady flow. We examined mechanisms of colloid mobilization from an intact, unsaturated soil core during relatively steady flow. We collected the core from a site where soils contain 26% clay and infiltration occurs only at capil ...
DOI:
10.2136/vzj2005.0102

7. Water Infiltration and Redistribution in Soil Aggregate Packings

Author:
A. Carminati; H. Flühler
Source:
Vadose zone journal 2009 v.8 no.1 pp. 150-157
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; vadose zone; infiltration (hydrology); soil aggregates; porous media; soil pore system; radiography;     Show all 7 Subjects
Abstract:
... Aggregation of soil particles is crucial for water flow in the vadose zone. Recent studies demonstrated that the unsaturated water flow through an aggregate pair is controlled by the contacts between aggregates. In these studies, the hydraulic conductivity of an aggregate pair was calculated as the harmonic mean of the conductivities of one aggregate and one contact, and it was fitted increasing t ...
DOI:
10.2136/vzj2008.0077

8. Foam Delivery of Amendments for Vadose Zone Remediation: Propagation Performance in Unsaturated Sediments

Author:
Lirong Zhong; Jim E. Szecsody; Fred Zhang; Shas V. Mattigod
Source:
Vadose zone journal 2010 v.9 no.3 pp. 757-767
ISSN:
1539-1663
Subject:
unsaturated flow,   etc   ; soil injection; soil remediation; soil pore system; soil water content; bubbles; spatial distribution; unsaturated conditions; viscosity; soil amendments; liquids; water; foams; soil transport processes; vadose zone; permeability;     Show all 16 Subjects
Abstract:
... Foam delivery of remedial amendments is potentially useful for vadose zone remediation because aqueous amendments are delivered while a low water content is maintained in the treated zones. The transport behavior of foam in the vadose zone has not been well studied. Benchtop-scale column tests were conducted to investigate foam transport, foaming gas and liquid propagation, pressure buildup and di ...
DOI:
10.2136/vzj2010.0007