SPECIAL SECTION: RESEARCH ADVANCES IN VADOSE ZONE HYDROLOGY THROUGH SIMULATIONS WITH THE TOUGH CODES:

Stefan Finsterle and Curtis M. Oldenburg

Research Advances in Vadose Zone Hydrology through Simulations with the TOUGH Codes: Preface from the Guest Editors
The guest editors introduce this issue's special section on the role of the TOUGH modeling codes in vadose zone hydrology.
Vadose Zone J 2004 3: 737. [Full Text] [PDF]  

Karsten Pruess

The TOUGH Codes—A Family of Simulation Tools for Multiphase Flow and Transport Processes in Permeable Media
The TOUGH codes are widely used for numerical simulation of nonisothermal, multiphase flows in porous and fractured media. This article reviews the historical background of code development, the mathematical models and approaches, solution techniques, and main applications of the codes.
Vadose Zone J 2004 3: 738-746. [Abstract] [Full Text] [Figures Only] [PDF]  

Stefan Finsterle

Multiphase Inverse Modeling: Review and iTOUGH2 Applications
Inverse modeling faces specific challenges when applied to highly heterogeneous multiphase flow systems. Topics covered in this review include historical remarks, parameterization issues, representation of heterogeneity, and applications of the multiphase simulation-optimization code iTOUGH2.
Vadose Zone J 2004 3: 747-762. [Abstract] [Full Text] [Figures Only] [PDF]  

Alan L. Flint and Kevin M. Ellett

The Role of the Unsaturated Zone in Artificial Recharge at San Gorgonio Pass, California
Characteristics of the unsaturated zone play a significant role in site suitability for artificial recharge. A case study is presented in which field and laboratory measurements are integrated into a conceptual and numerical model to show the interaction between the artificially recharged water and the layer stratigraphy of the underlying unsaturated zone.
Vadose Zone J 2004 3: 763-774. [Abstract] [Full Text] [Figures Only] [PDF]  

Michael J. Singleton, Eric L. Sonnenthal, Mark E. Conrad, Donald J. DePaolo, and Glendon W. Gee

Multiphase Reactive Transport Modeling of Seasonal Infiltration Events and Stable Isotope Fractionation in Unsaturated Zone Pore Water and Vapor at the Hanford Site
Seasonal infiltration in semiarid regions leads to vadose zone stable isotope profiles distinct from those for arid conditions. A new reactive transport model is used along with data from sediment cores to discover relations between net infiltration and isotopic shift in vadose zone waters.
Vadose Zone J 2004 3: 775-785. [Abstract] [Full Text] [Figures Only] [PDF]  

Niclas Bockgård and Auli Niemi

Role of Rock Heterogeneity on Lateral Diversion of Water Flow at the Soil–Rock Interface
Flow diversion at the interface between soil and bedrock is important for the water budget of the bedrock. A numerical model of variably saturated flow is used to investigate the flow through the soil-bedrock interface, considering hydraulic properties of the bedrock to be either homogeneous or heterogeneous.
Vadose Zone J 2004 3: 786-795. [Abstract] [Full Text] [Figures Only] [PDF]  

Yu-Shu Wu, Guoping Lu, Keni Zhang, and G. S. Bodvarsson

A Mountain-Scale Model for Characterizing Unsaturated Flow and Transport in Fractured Tuffs of Yucca Mountain
A dual-continuum model is developed to simulate large-scale three-dimensional fluid flow and tracer transport in the unsaturated zone of Yucca Mountain. The effects of different conceptual models and assumed infiltration conditions on the simulated flow within the unsaturated zone of the mountain are investigated.
Vadose Zone J 2004 3: 796-805. [Abstract] [Full Text] [Figures Only] [PDF]  

T. A. Ghezzehei, R. C. Trautz, S. Finsterle, P. J. Cook, and C. F. Ahlers

Modeling Coupled Evaporation and Seepage in Ventilated Cavities
Seepage of liquid water into waste emplacement cavities is an important factor affecting the long-term safety of the proposed nuclear waste repository at Yucca Mountain, Nevada. This paper is concerned with modeling coupled seepage and evaporation into cavities and model calibration against field seepage data.
Vadose Zone J 2004 3: 806-818. [Abstract] [Full Text] [Figures Only] [PDF]  

Jens T. Birkholzer, Sumit Mukhopadhyay, and Yvonne W. Tsang

Modeling Seepage into Heated Waste Emplacement Tunnels in Unsaturated Fractured Rock
A TOUGH2 dual-permeability simulation model was used to predict the amount of percolation water that could potentially seep into underground waste storage tunnels at Yucca Mountain. Model simulations are performed to assess the effect of heat generated from stored waste on the potential for seepage.
Vadose Zone J 2004 3: 819-836. [Abstract] [Full Text] [Figures Only] [PDF]  

Christine Doughty and Karsten Pruess

Modeling Supercritical Carbon Dioxide Injection in Heterogeneous Porous Media
The sequestration of carbon dioxide in liquid-saturated, brine-bearing geologic formations produces a multiphase, multicomponent environment akin to the vadose zone. Strong heterogeneity leads to preferential flow effects. We numerically model the flow and transport processes associated with the sequestration process.
Vadose Zone J 2004 3: 837-847. [Abstract] [Full Text] [Figures Only] [PDF]  

Curtis M. Oldenburg and André J. A. Unger

Coupled Vadose Zone and Atmospheric Surface-Layer Transport of Carbon Dioxide from Geologic Carbon Sequestration Sites
A coupled subsurface and atmospheric surface-layer model is presented for simulating carbon dioxide leakage and seepage from geologic carbon sequestration sites. Simulation results show that atmospheric dispersion effectively dilutes small carbon dioxide seepage fluxes, and rainfall infiltration can cause a reflux of carbon dioxide back to the subsurface.
Vadose Zone J 2004 3: 848-857. [Abstract] [Full Text] [Figures Only] [PDF]  

Yingqi Zhang, Curtis M. Oldenburg, and Sally M. Benson

Vadose Zone Remediation of Carbon Dioxide Leakage from Geologic Carbon Dioxide Sequestration Sites
Numerical simulation is used to evaluate alternative strategies for remediation of carbon dioxide plumes in the event that carbon dioxide leakage from deep geologic carbon sequestration sites reaches the vadose zone. Both passive and active remediation methods are examined.
Vadose Zone J 2004 3: 858-866. [Abstract] [Full Text] [Figures Only] [PDF]  

Jeongkon Kim, Franklin W. Schwartz, Tianfu Xu, Heechul Choi, and In S. Kim

Coupled Processes of Fluid Flow, Solute Transport, and Geochemical Reactions in Reactive Barriers
Modeling studies using TOUGHREACT are presented to investigate complex patterns of coupling between fluid flow and mass transport in porous media. Results illustrate effects of geochemical reactions and density differences on plume migration.
Vadose Zone J 2004 3: 867-874. [Abstract] [Full Text] [Figures Only] [PDF]  

Alfredo Battistelli

Modeling Biodegradation of Organic Contaminants under Multiphase Conditions with TMVOCBio
Biodegradation reactions have an important role in controlling the migration and retention of organic contaminant mixtures in the subsurface. A numerical approach is presented which allows modeling of coupled flow, transport, and reactive processes under multiphase conditions, such as those present near hydrocarbon and organic solvent spill areas.
Vadose Zone J 2004 3: 875-883. [Abstract] [Full Text] [Figures Only] [PDF]  

Quanlin Zhou, Jens T. Birkholzer, Iraj Javandel, and Preston D. Jordan

Modeling Three-Dimensional Groundwater Flow and Advective Contaminant Transport at a Heterogeneous Mountainous Site in Support of Remediation
A groundwater flow model was calibrated to simulate flow and transport at an urbanized, mountainous site contaminated by volatile organic compounds. The model accounted for the complex geological units and the complex recharge variability. The model was used to evaluate interim remediation measures.
Vadose Zone J 2004 3: 884-900. [Abstract] [Full Text] [Figures Only] [PDF]  

Terhi Kling, Juhani Korkealaakso, and Jukka Saarenpää

Application of Nonisothermal Multiphase Modeling to In Situ Soil Remediation in Söderkulla
Nonisothermal multiphase modeling is applied to in situ soil remediation by thermally enhanced soil vapor extraction. A remediation experiment is presented where modeling was used in the planning and control of the remediation system as well as for integration of information obtained from field investigations.
Vadose Zone J 2004 3: 901-908. [Abstract] [Full Text] [Figures Only] [PDF]  

Harold Vigneault, René Lefebvre, and Miroslav Nastev

Numerical Simulation of the Radius of Influence for Landfill Gas Wells
The TOUGH2 LGM numerical simulator was used to quantify the efficiency of landfill gas recovery wells for unlined landfills. The radius of influence of gas recovery wells, an important well design parameter, was quantified and related to various landfill system characteristics. Results will help with the design of landfill gas recovery systems.
Vadose Zone J 2004 3: 909-916. [Abstract] [Full Text] [Figures Only] [PDF]  

Patricia M. Gallagher and Stefan Finsterle

Physical and Numerical Model of Colloidal Silica Injection for Passive Site Stabilization
Injection of colloidal silica grout is a means to stabilize soils susceptible to liquefaction during earthquakes. Data from a sandbox experiment were used in combination with numerical modeling to identify the key parameters affecting stabilizer migration.
Vadose Zone J 2004 3: 917-925. [Abstract] [Full Text] [Figures Only] [PDF]  

ORIGINAL RESEARCH:

James L. Starr and Dennis J. Timlin

Using High-Resolution Soil Moisture Data to Assess Soil Water Dynamics in the Vadose Zone
Seasonal changes in soil water storage, drainage, and water uptake were quantified using high frequency soil water measurements under no till and plow till corn. Results show both the value and limitation of near-continuous real-time soil water data for modeling the fate of water in varying soil, crop, and season conditions.
Vadose Zone J 2004 3: 926-935. [Abstract] [Full Text] [Figures Only] [PDF]  

Kyle W. Blasch, Ty P. A. Ferré, and John P. Hoffmann

A Statistical Technique for Interpreting Streamflow Timing Using Streambed Sediment Thermographs
A bed sediment thermograph method for monitoring the onset and cessation of ephemeral streamflow timing is described. Sensor depth is the most critical factor for differentiating between the primary thermal transport mechanisms. Procedures for determining the optimal depths are presented.
Vadose Zone J 2004 3: 936-946. [Abstract] [Full Text] [Figures Only] [PDF]  

Gerrit H. de Rooij, Roy T. A. Kasteel, Andreas Papritz, and Hannes Flühler

Joint Distributions of the Unsaturated Soil Hydraulic Parameters and their Effect on Other Variates
A new method is presented to identify transformations that lead to a multivariate normal distribution of transformed soil hydraulic parameters. From this, the distribution of other variants (e.g., the water content and soil hydraulic conductivity at given pressure heads) are derived analytically and by Monte Carlo simulation.
Vadose Zone J 2004 3: 947-955. [Abstract] [Full Text] [Figures Only] [PDF]  

M. H. Young, E. V. McDonald, T. G. Caldwell, S. G. Benner, and D. G. Meadows

Hydraulic Properties of a Desert Soil Chronosequence in the Mojave Desert, USA
Desert pavements in warm, arid environments are hypothesized as controlling infiltration and hence the overall hydrologic conditions in the soil profile. Tension infiltrometer studies showed that hydraulic properties were significantly affected by age of the uppermost soil layer, illustrating the effect of pedological development.
Vadose Zone J 2004 3: 956-963. [Abstract] [Full Text] [Figures Only] [PDF]  

Waduwawatte Bodhinayake, Bing Cheng Si, and Kosuke Noborio

Determination of Hydraulic Properties in Sloping Landscapes from Tension and Double-Ring Infiltrometers
The capability of tension and double-ring infiltrometers to estimate soil hydraulic properties on sloping soil surface is examined using in situ measurements and three-dimensional simulation of variable saturated flow. Results indicate that slope does not significantly affect cumulative infiltration rate for slopes up to 20%.
Vadose Zone J 2004 3: 964-970. [Abstract] [Full Text] [Figures Only] [PDF]  

S. Bitterlich, W. Durner, S. C. Iden, and P. Knabner

Inverse Estimation of the Unsaturated Soil Hydraulic Properties from Column Outflow Experiments Using Free-Form Parameterizations
Hydraulic properties of soils are identified by a new method using inverse modeling of transient water flow without fixed functional forms for water retention and hydraulic conductivity. The method is accurate and robust, and has a large degree of flexibility in the resulting functional descriptions.
Vadose Zone J 2004 3: 971-981. [Abstract] [Full Text] [Figures Only] [PDF]  

Marshall Reiter

Continuous Temperature Logging in Air across the Deep Vadose Zone
Temperatures taken in the deep desert vadose zone may reveal surface temperature change with time, although processes influencing surface temperature may be uncertain. A depth resolution of 1 m allows the fitting of data with expressions that can relate to possible timing and magnitude of surface temperature changes.
Vadose Zone J 2004 3: 982-989. [Abstract] [Full Text] [Figures Only] [PDF]  

Michael R. Rosen, Robert R. Reeves, Steven Green, Brent Clothier, and Nigel Ironside

Prediction of Groundwater Nitrate Contamination after Closure of an Unlined Sheep Feedlot
A sheep feedlot in New Zealand was found to be the source of nitrate contamination of the underlying aquifer, leading to the eventual shutdown of the feedlot. Prediction of aquifer water quality recovery time following feedlot shutdown was preformed using the SPASMO model with collected vadose zone parameters.
Vadose Zone J 2004 3: 990-1006. [Abstract] [Full Text] [Figures Only] [PDF]  

Tanja N. Williamson, Brent D. Newman, Robert C. Graham, and Peter J. Shouse

Regolith Water in Zero-Order Chaparral and Perennial Grass Watersheds Four Decades after Vegetation Conversion
Water potential and residual flux differed between chaparral areas and those converted to grass, indicating recharge below grass in average or wetter years. Flux differences correlate with horizon boundaries and illustrate the link between soil water and changes in soil properties.
Vadose Zone J 2004 3: 1007-1016. [Abstract] [Full Text] [Figures Only] [PDF]  

Daizo Tsutsumi, Ken'ichiro Kosugi, and Takahisa Mizuyama

Three-Dimensional Modeling of Hydrotropism Effects on Plant Root Architecture along a Hillslope
Plant root development along hillslopes was simulated by a new model that includes effects of gravitropism, hydrotropism, and circumnutation. Comparison of model results with field observations suggests that asymmetric root architecture was attributed to hydrotropism.
Vadose Zone J 2004 3: 1017-1030. [Abstract] [Full Text] [Figures Only] [PDF]  

Violeta Lima-Vivancos and Vaughan R. Voller

Two Numerical Methods for Modeling Variably Saturated Flow in Layered Media
The simulation of the drainage of an initially saturated layered soil column is studied using two numerical methods. One method is a conservative finite difference scheme using a novel treatment of material interfaces. The other method is an ODE shooting solution of Richards' equation.
Vadose Zone J 2004 3: 1031-1037. [Abstract] [Full Text] [Figures Only] [PDF]  

Mark Bakker and John L. Nieber

Analytic Element Modeling of Cylindrical Drains and Cylindrical Inhomogeneities in Steady Two-Dimensional Unsaturated Flow
The analytic element method is applied to solve the quasilinearized Richards equation for unsaturated flow domains containing arbitrarily located cylindrical inhomogeneities and cylindrical drains. The solution is applied to show the effect of multiple inhomogeneities and drains on flow patterns in the vadose zone.
Vadose Zone J 2004 3: 1038-1049. [Abstract] [Full Text] [Figures Only] [PDF]  

Martin F. Helmke, William W. Simpkins, and Robert Horton

Experimental Determination of Effective Diffusion Parameters in the Matrix of Fractured Till
Solute transport through materials of low permeability is often governed by diffusion. In this study, radial diffusion cells are used to determine effective diffusion parameters in the matrix of fractured tills using multiple conservative tracers.
Vadose Zone J 2004 3: 1050-1056. [Abstract] [Full Text] [Figures Only] [PDF]  

BOOK REVIEWS:

Ole Wendroth

Multivariate Analysis of Ecological Data using CANOCO.
Vadose Zone J 2004 3: 1057. [Full Text] [PDF]  

To see an article, click its [Full Text] link. To review many abstracts, check the boxes to the left of the titles you want, and click the 'Get All Checked Abstract(s)' button. To see one abstract at a time, click its [Abstract] link.