Source: UNIV OF IDAHO submitted to NRP
CHARACTERIZATION OF FLOW AND TRANSPORT PROCESSES IN SOILS AT DIFFERENT SCALES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
0191952
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
W-188
Project Start Date
Jul 1, 2002
Project End Date
Sep 30, 2004
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIV OF IDAHO
875 PERIMETER DRIVE
MOSCOW,ID 83844-9803
Performing Department
PLANT SOIL & ENTOMOLOGICAL SCI
Non Technical Summary
Some of the most productive agricultural soils contain appreciable amounts of active clay minerals and exhibit shrink-swell behavior in response to changes in soil water content and chemical composition of the soil solution, leading to surface sealing, impaired infiltration, erosion, and preferential flow. This research addresses the unresolved problem of linking fundamental theory on clay shrink-swell behavior with pore-scale geometrical, hydrostatic, and hydrodynamic considerations towards development of predictive models for hydraulic functions of swelling soils.
Animal Health Component
10%
Research Effort Categories
Basic
25%
Applied
10%
Developmental
65%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110201070%
1020110205030%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
0110 - Soil;

Field Of Science
2010 - Physics; 2050 - Hydrology;
Goals / Objectives
1. To study relationships between flow and transport properties or processes and the spatial and temporal scales at which these are observed. 2. To develop and evaluate instrumentation and methods of analysis for characterization of flow and transport at different scales.
Project Methods
The study is aimed at developing a framework for predicting hydraulic properties of swelling soils by building a comprehensive geometrical picture of the arrangement and evolution of clay fabric mixed with other textural constituents and linked to a physico-chemical model. Clay fabric will be considered as an assembly of colloidal-size stacks of lamellae (tactoids) whose spatial organization and the spacing between individual clay sheets are functions of clay hydration state quantifiable via the disjoining pressure formalism and dominated by a large electrostatic repulsive force. Silt and sand textural constituents will be represented as rigid spheres interspaced by clay fabric in two basic configurations of "expansive" and "reductive" unit cells. Bulk media properties such as porosity and surface area provide constraints for the idealized geometry. A statistical upscaling scheme based on sand and silt particle size distributions and constrained by clay content, total porosity, and mass-volume "universal" relationships will be employed to derive sample- and profile-scale liquid retention and hydraulic conductivity functions. At the profile-scale effects of overburden on depth-dependent shrink-swell behavior, and formation of near-surface crack networks and their impact on surface intake properties will be considered. Experiments are designed to determine shrink-swell behavior and hydraulic properties of artificial clay-glass bead mixtures and several natural soils by using unconfined and confined measurement techniques. Direct microscopic observations of the spatial distribution of clay domains among sand and silt fractions (for different clay contents and ambient conditions) will be used to test and refine key modeling assumptions.

Progress 07/01/02 to 09/30/04

Outputs
We made the following major contributions to the W-188 Multistate Project: (1) Development of a physically-based model for hydraulic properties of fractured porous media. Standard models for hydraulic functions of partially saturated fractured porous media (FPM) often rely on macroscopic continuum representation and embrace constitutive relationships originally developed for homogeneous porous media to describe hydraulic behavior of dual (or multi) continua FPM. Such approaches lead to inconsistencies due to neglect of underlying physical processes governing liquid retention and flow in the vastly different pore spaces. We developed a framework that considers equilibrium liquid configurations in dual continuum pore space as the basis for calculation of liquid saturation and introduction of hydrodynamic considerations. FPM cross-sectional pore space is represented by a bimodal size distribution reflecting two disparate populations of matrix pores and fracture apertures (with rough-walled surfaces). Three laminar flow regimes are considered. (2) Development of a physically-based model for pore space evolution in expansive clay soils. Changes in volume and pore space induced by the shrink-swell behavior of clay minerals present a challenge to predictive modeling of hydraulic properties of clayey soils. We developed a novel framework that combines physico-chemical processes with pore scale geometrical, hydrostatic, and hydrodynamic considerations toward prediction of constitutive hydraulic relationships for swelling porous media. In course of this project we introduced novel technology for measurement of hydraulic conductivity and swelling potential of expansive soils to the soil science community. (3) Investigation of flow and distribution of fluids in porous plant growth media in microgravity. Despite 20 years of plant research in space, we lack understanding of basic fluid distribution and flow through porous media in microgravity. Plants are essential for closed life support systems on long duration space missions. Even though plants/crops would be grown in a protected habitat in transit vehicles or on the surface of Moon and Mars, the environment is hostile to growth unless conditions are carefully controlled. The added complication that methods and procedures for water and nutrient management are necessarily modified under micro- or reduced gravity conditions presents a unique challenge that has yet to be met. Within this collaborative project we were able to scientifically identify causes for limited progress with plant growth experiments in space, and to provide guidelines for the developed of engineered plant growth media for reduced gravity and coupling of rhizospheric processes. Results were disseminated through 9 refereed journal articles and book chapters, 5 conference proceedings, and numerous abstracts and presentations.

Impacts
The potential impact of our contributions can be specified as follows: (1) The ability to predict seepage through fractured formations becomes increasingly important for the design of subsurface waste repositories such as the potential high-level nuclear waste repository at Yucca Mountain, Nevada. Our model can be utilized to predict potential seepage based on climatic conditions, thereby contributing to the design and safe operation of potential underground storage facilities. (2) Predictive capabilities of pore space changes and associated hydraulic properties are crucial for management of agricultural soils with appreciable amount of active clay minerals. Results of our efforts should significantly contribute to improved salinity and sodicity management practices in irrigated agricultural areas. Furthermore, insights gained from this study will enhance understanding of clay dispersion and surface sealing, and lead to improved management guidelines for prevention of soil erosion and colloid facilitated transport of agrochemicals. (3) Understanding of fluid behavior under microgravity conditions allows the development of engineered plant growth media that will be used for NASA's advanced life support systems for future long-duration space missions.

Publications

  • Tuller, M. and Or, D. 2004. Water retention and characteristic curve. In Hillel, D. (Ed.), Encyclopedia of Soils in the Environment, Volume 4, Elsevier Ltd., Oxford, U.K., pp. 278-289.
  • Or, D., Tuller, M. and Wraith, J.M. 2004. Water potential. In Hillel. D. (Ed.), Encyclopedia of Soils in the Environment, Volume 4, Elsevier Ltd., Oxford, U.K., pp. 270-277.
  • Or, D. and Tuller, M. 2004. Capillarity. In Hillel, D. (Ed.), Encyclopedia of Soils in the Environment, Volume 1, Elsevier Ltd., Oxford, U.K., pp. 155-163.
  • Or, D., Tuller, M. and Jones, S.B. 2004. Liquid-Gas Interfacial Configurations in Angular Pores under Microgravity. Proceedings of the 9th Biennial ASCE Aerospace Division International Conference on Engineering, Construction, and Operations in Challenging Environments, March 7-10, League City, TX. ASCE, Reston, VG, pp. 346-353.
  • Steinberg, S., Alexander, I., Or, D., Daidzic, N., Jones, S., Reddi, L., Tuller, M., Kluitenberg, G. and Xiao, M. 2004. Flow and Distribution of Fluid Phases Through Porous Plant Growth Media in Microgravity. Proceedings of the 9th Biennial ASCE Aerospace Division International Conference on Engineering, Construction, and Operations in Challenging Environments, March 7-10, League City, TX. ASCE, Reston, VG, pp. 325-332.
  • Tuller, M. and Or, D. 2004. A Universal Slope for Soil Water Characteristic Curves at Low Water Content. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 4821.
  • Tuller, M. and Islam, M.R. 2004. Methods for monitoring solute transport. In J. Alvarez-Benedi and R. Munoz-Carpena, Eds. Soil - Water Solute Process Characterization: An integrated Approach, CRC Press, pp. 309-355.
  • Viola, R., Tuller, M. and Islam, M.R. 2004. Microscopic Observations of Pore Space Geometry in Clay-Sand Mixtures under Varying Hydration States. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 4546.
  • Ghebrehawariat, K., Tuller, M. and Or, D. 2004. Saturated Hydraulic Conductivity and Volume Change of Clay-Sand Mixtures. SSSA Annual Meeting Abstracts, Oct. 31 - Nov. 4, Seattle, WA. On CD, abstract 4835.
  • Islam, M.R., Tuller, M. and Steinberg, S.L. 2004. Chemical and Mineralogical Composition of Baked Ceramic Aggregates Used as Plant Growth Media in Space. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 5991.
  • Gebrenegus, T., Tuller, M. and Muhunthan, B. 2004. Visualization and Quantification of Spatial Phase Arrangement in Bentonite-Sand Mixtures with X-Ray Computed Tomography. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 4860.
  • Or, D., Jones, S.B., Tuller, M., Steinberg, S.L., Alexander, I., Daidzic, N., Reddi, L.N., Kluitenberg, G., Ogden, F.L. and Heinse, R. 2004. Unsaturated Flow in Zero Gravity - Lessons and Challenges. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 5102.
  • Heinse, R., Jones, S.B., Humphries, S.D., Mace, R.W., Steinberg, S.L., Tuller, M., Newman, R. and Or, D. 2004. Porous Media Water Retention and Saturated Hydraulic Conductivity During Parabolic Flight Induced Microgravity. SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, Seattle, WA. On CD, abstract 5867.
  • Gebrenegus, T., Tuller, M. and Muhunthan, B. 2004. Visualization of Spatial and Transient Phase Distributions in Porous Materials with X-Ray Computed Tomography. INRA Environmental & Subsurface Science Symposium "Environmental and Subsurface Science Applied to Energy, Nuclear, and National Security Research", September 20-22, 2004, Spokane, WA, http://www.b-there.com/breg/esss04/Poster_Beyene.doc.


Progress 01/01/03 to 12/31/03

Outputs
After development of a geometrical pore space evolution model linked to hydration state, and introduction of hydrostatic and hydrodynamic considerations to model liquid retention, hydraulic conductivity, and swelling behavior of clay soils we conducted a comprehensive experiment series to evaluate effects of clay type, clay content, solution chemistry and solution concentration on swelling behavior and hydraulic properties. We employed a latest technology flexible wall permeameter and volume change apparatus to measure hydraulic conductivity and swelling properties of bentonite-sand mixtures. We used solutions varying in molarity and ion valence to investigate the effects of solution concentration and type. The measurements were performed for bentonite contents ranging from 0 to 100%. The measurements were used to refine our pore-scale model, and to develop a statistical upscaling scheme to predict sample-scale hydraulic behavior. In this context we started measurements at the new WSU Computed Tomography (CT) facility to resolve and introduce anisotropic hydraulic behavior. A recent collaboration with the INEEL Geocentrifuge facility in Idaho Falls allows access to a relatively large centrifuge that allows measurements on large specimens. These measurements will lead to the development of and upscaling concept for prediction of profile-scale properties. These efforts are partially supported by a NSF-EPSCoR and an USGS-IWRRI grant. We continued to work on flow phenomena in structured soils that led to a refereed publication in Advances in Water Resources, and conducted KC135 flight experiments in Houston, TX to investigate liquid behavior in porous plant growth media under microgravity. The flight experimental data are used in combination with physically based models to design root modules and growth chambers suitable to support plant growth at the International Space Station and for other space exploration. This project is supported by NASA. Research findings were disseminated through 2 refereed journal articles, 4 refereed book chapters, and numerous presentations at national and international symposia and meetings.

Impacts
The project on swelling soils will significantly contribute to improved predictions of water flow and solute interactions in agricultural soils with appreciable amount of clay minerals, and lead to improved salinity and sodicity management practices in irrigated agricultural areas. Furthermore, insights gained from this study will enhance understanding of clay dispersion and surface sealing, and lead to improved management guidelines for prevention of soil erosion, and associated colloid facilitated transport of agrochemicals. In extreme cases, improved ability for prediction of the onset of surface runoff from clay soils at the field and watershed scale can prevent catastrophic events, such as flooding and could provide early warning and save lives and property. Besides agricultural and environmental applications the project also provides new insights for geotechnical engineering. Structural damage to buildings and roads due to active clay soils is an important economic factor. Improved predictions of swelling behavior could prevent such damages and save millions of dollars every year. Another potential application is the development of design criteria for clay liners used to seal waste repositories to prevent leaching and migration of toxic contaminants to aquifers and other water resources.

Publications

  • Or, D. and Tuller, M. 2003. Reply to comment on 'Cavitation during desaturation of porous media under tension' by Toker, N.K., J.T. Germaine, and P.J. Culligan. Water Resour. Res., 39(11):1306.
  • Or, D. and Tuller, M. 2003. Hydraulic conductivity of unsaturated fractured porous media: Flow in a cross-section. Advances in Water Resources, 26(8):883-898.
  • Steinberg, S.L., Jones, S.B., Or, D., Daidzic, N.E., Tuller, M. and Ogden, F. 2003. Tensiometer measurements under variable gravity conditions, SSSA Annual Meeting Abstracts, November 2-6, Denver, Colorado.
  • Jones, S.B., Or, D., Tuller, M., Steinberg, S., Humphries, S.D., Bingham, G.E., Daidzic, N.E. and Reddi, L.N. 2003. Influence of Variable Gravity on Liquid Configurations in Micromodels, SSSA Annual Meeting Abstracts, November 2-6, Denver, Colorado.
  • Tuller, M., Gebrehawariat, K., Or, D. and Muhunthan, B. 2003. Experimental Studies on Swelling and Saturated Flow Behavior of Clay Soils. SSSA Annual Meeting Abstracts, November 2-6, Denver, Colorado.
  • Steinberg, S.L., Alexander, J.I.D., Daidzic, N., Jones, S., Kluitenberg, G., Or, D., Reddi, L. and Tuller, M. 2003. Flow and Distribution of Fluid Phases through Porous Plant Growth Media in Microgravity. Bioastronautics Investigator's Workshop. Abstract Volume p. 121. Jan. 13-15, Galveston, Texas.


Progress 01/01/02 to 12/31/02

Outputs
We made significant progress during the reporting period towards a comprehensive framework for modeling hydraulic behavior of clay soils. After development of a geometrical pore space evolution model that considers a hierarchy of pore spaces in the clay matrix and between other textural components (e.g., sand or silt grains) and is linked to soil hydration state we introduced hydrostatic and hydrodynamic considerations to model liquid retention and swelling behavior and to predict saturated hydraulic conductivity of clay soils at the pore and sample scales. Preliminary calculations and comparison with measured data show the great potential of the proposed approach. To further refine the model and to evaluate effects of clay type, clay content, solution chemistry and solution concentration on swelling behavior and hydraulic properties we recently started a series of laboratory experiments using a state of the art, fully automated flexible wall permeameter. Preliminary measurements and comparison with model calculations are very promising. Currently we are working on statistical upscaling schemes to predict swelling behavior and hydraulic conductivity at the sample and profile scales. Collaboration with the Geotechnical Engineering group at Washington State University allows us access to a latest technology Computed Tomography (CT) System that we apply to resolve and introduce anisotropic behavior due to directional orientation of clay platelets. Some of the physically based phenomena investigated for swelling soils were also applied to predict hydraulic functions for structured soils and fractured rocks. Pore scale liquid behavior calculated from thermodynamic principles also builds the bases for a model we developed during the reporting period to support the design of artificial plant growth media for advanced life support systems in space. Previous plant growth experiments during space flight revealed difficulties with water, nutrient, and air supply to plant roots. These limitations were attributed to design flaws due to limited understanding of liquid behavior and configuration in particulate porous media under reduced gravity. Microgravity could affect pore-scale liquid organization by enhancing phase entrapment and changing interfacial configurations. As a first step we were able to solve the Augmented Young-Laplace AYL without gravity term to predict liquid behavior under reduced gravity. These insights will be used in combination with KC-135 flight experiments to design root modules and growth chambers suitable to support plant growth in space. This project is supported by NASA.

Impacts
The project on swelling soils will significantly contribute to improved predictions of water flow and solute interactions in agricultural soils with appreciable amount of clay minerals, and lead to improved salinity and sodicity management practices in irrigated agricultural areas. Furthermore, insights gained from this study will enhance understanding of clay dispersion and surface sealing, and lead to improved management guidelines for prevention of soil erosion, and associated colloid facilitated transport of agrochemicals. In extreme cases, improved ability for prediction of the onset of surface runoff from clay soils at the field and watershed scale can prevent catastrophic events, such as flooding and could provide early warning and save lives and property. Besides agricultural and environmental applications the project also provides new insights for geotechnical engineering. Structural damage to buildings and roads due to active clay soils is an important economic factor. Improved predictions of swelling behavior could prevent such damages and save millions of dollars every year. Another potential application is the development of design criteria for clay liners used to seal waste repositories to prevent leaching and migration of toxic contaminants to aquifers and other water resources. Our investigations and modeling efforts regarding liquid behavior in plant growth substrates under reduced gravity should significantly contribute to the design of root modules for plant growth and advanced life support systems in space.

Publications

  • Tuller, M., and D. Or. 2002. Hydraulic Functions for Swelling Soils: Pore Scale Considerations. Journal of Hydrology (in press).
  • Tuller, M., and D. Or. 2002. Unsaturated Hydraulic Conductivity of Structured Porous Media: A Review of Liquid Configuration-Based Models. Vadose Zone Journal, 1:14-37.
  • Or, D., and M. Tuller. 2002. Cavitation during desaturation of porous media under tension. Water Resour. Res. 38(5):19.