A Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone
A Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone

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Published: 1999

Total Pages: 5

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(1) To determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. (2) To introduce a new approach to the multiscale characterization of flow and transport in fractured basalt vadose zones and to develop physically based conceptual models on a hierarchy of scales. The following activities are indicative of the success in meeting the project s objectives: A series of ponded infiltration tests, including (1) small-scale infiltration tests (ponded area 0.5 m2) conducted at the Hell s Half Acre site near Shelley, Idaho, and (2) intermediate-scale infiltration tests (ponded area 56 m2) conducted at the Box Canyon site near Arco, Idaho. Laboratory investigations and modeling of flow in a fractured basalt core. A series of small-scale dripping experiments in fracture models. Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from nonlinear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; Development of a conceptual model and mathematical and numerical algorithms for flow and transport that incorporate (1) the spatial variability of heterogeneous porous and fractured media, and (2) the description of the temporal dynamics of flow and transport, both of which may be chaotic. Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial heterogeneity and flow phenomena are affected by nonlinear dynamics, and in particular, by chaotic processes. The scientific and practical value of this approach is that we can predict the range within which the parameters of flow and transport change with time in order to design and manage the remediation, even when we can not predict the behavior at any point or time.

Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone
Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone

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Published: 1999

Total Pages: 5

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DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has led to the contamination of (or threatens to contaminate) underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is the determination of the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently, through narrow pathways, driven by variations in environmental conditions. These preferential flow pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following activities: Development of multi scale conceptual models and mathematical and numerical algorithms for flow and transport, which incorporate both (a) the spatial variability of heterogeneous porous and fractured media and (b) the temporal dynamics of flow and transport; Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow; Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils and remediation efforts. This approach is based on the consideration of multi scale spatial heterogeneity and flow phenomena that are affected by nonlinear dynamics, and in particular, chaotic processes. The scientific and practical value of this approach is that we can predict the range within, which the parameters of flow and transport change with time, which allows us to design and manage the remediation even when we cannot predict the behavior at any point or time.

Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1998 Annual Progress Report
Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1998 Annual Progress Report

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Published: 1998

Total Pages: 3

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DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has lead to the contamination of or threatens to contaminate underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is to determine the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently through narrow pathways driven by variations in environmental conditions. These preferential pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following Activities (1) Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; (2) Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; (3) Development of a conceptual model and mathematical and numerical algorithms for flow and transport, which incorporate both: (a) the spatial variability of heterogeneous porous and fractured media, and (b) the description of the temporal dynamics of flow and transport, which may be chaotic; and (4) Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial heterogeneity and flow phenomena are affected by non-linear dynamics, and in particular, chaotic processes. The scientific and practical value of this approach is that the authors can predict the range within which the parameters of flow and transport change with time in order to design and manage the remediation, even when the authors can not predict the behavior at any point or time. This progress report summarizes work after 1.5 years of a 3-year project.

A Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1997 Annual Progress Report
A Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1997 Annual Progress Report

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Published: 1997

Total Pages: 16

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Understanding subsurface flow and transport processes is critical for effective assessment, decision-making, and remediation activities for contaminated sites. However, for fluid flow and contaminant transport through fractured vadose zones, traditional hydrogeological approaches are often found to be inadequate. In this project, the authors examine flow and transport through a fractured vadose zone as a deterministic chaotic dynamical process, and develop a model of it in these terms. Initially, they examine separately the geometric model of fractured rock and the flow dynamics model needed to describe chaotic behavior. Ultimately they will put the geometry and flow dynamics together to develop a chaotic-dynamical model of flow and transport in a fractured vadose zone. They investigate water flow and contaminant transport on several scales, ranging from small-scale laboratory experiments in fracture replicas and fractured cores, to field experiments conducted in a single exposed fracture at a basalt outcrop, and finally to a ponded infiltration test using a pond of 7 by 8 m. In the field experiments, the authors measure the time-variation of water flux, moisture content, and hydraulic head at various locations, as well as the total inflow rate to the subsurface. Such variations reflect the changes in the geometry and physics of water flow that display chaotic behavior, which the authors try to reconstruct using the data obtained. In the analysis of experimental data, a chaotic model can be used to predict the long-term bounds on fluid flow and transport behavior, known as the attractor of the system, and to examine the limits of short-term predictability within these bounds. This approach is especially well suited to the need for short-term predictions to support remediation decisions and long-term bounding studies.

A Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1997 Progress Report and Presentations at the Annual Meeting, Ernest Orlando Lawrence Berkeley National Laboratory, December 3--4, 1997
A Chaotic-dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone. 1997 Progress Report and Presentations at the Annual Meeting, Ernest Orlando Lawrence Berkeley National Laboratory, December 3--4, 1997

Author:

Publisher:

Published: 1998

Total Pages: 278

ISBN-13:

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Understanding subsurface flow and transport processes is critical for effective assessment, decision-making, and remediation activities for contaminated sites. However, for fluid flow and contaminant transport through fractured vadose zones, traditional hydrogeological approaches are often found to be inadequate. In this project, the authors examine flow and transport through a fractured vadose zone as a deterministic chaotic dynamical process, and develop a model of it in these terms. Initially, the authors examine separately the geometric model of fractured rock and the flow dynamics model needed to describe chaotic behavior. Ultimately they will put the geometry and flow dynamics together to develop a chaotic-dynamical model of flow and transport in a fractured vadose zone. They investigate water flow and contaminant transport on several scales, ranging from small-scale laboratory experiments in fracture replicas and fractured cores, to field experiments conducted in a single exposed fracture at a basalt outcrop, and finally to a ponded infiltration test using a pond of 7 by 8 m. In the field experiments, they measure the time-variation of water flux, moisture content, and hydraulic head at various locations, as well as the total inflow rate to the subsurface. Such variations reflect the changes in the geometry and physics of water flow that display chaotic behavior, which they try to reconstruct using the data obtained. In the analysis of experimental data, a chaotic model can be used to predict the long-term bounds on fluid flow and transport behavior, known as the attractor of the system, and to examine the limits of short-term predictability within these bounds. This approach is especially well suited to the need for short-term predictions to support remediation decisions and long-term bounding studies. View-graphs from ten presentations made at the annual meeting held December 3--4, 1997 are included in an appendix to this report.

Conceptual Models of Flow and Transport in the Fractured Vadose Zone
Conceptual Models of Flow and Transport in the Fractured Vadose Zone

Author: National Research Council

Publisher: National Academies Press

Published: 2001-05-21

Total Pages: 398

ISBN-13: 0309170990

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Fluid flow and solute transport within the vadose zone, the unsaturated zone between the land surface and the water table, can be the cause of expanded plumes arising from localized contaminant sources. An understanding of vadose zone processes is, therefore, an essential prerequisite for cost-effective contaminant remediation efforts. In addition, because such features are potential avenues for rapid transport of chemicals from contamination sources to the water table, the presence of fractures and other channel-like openings in the vadose zone poses a particularly significant problem, Conceptual Models of Flow and Transport in the Fractured Vadose Zone is based on the work of a panel established under the auspices of the U.S. National Committee for Rock Mechanics. It emphasizes the importance of conceptual models and goes on to review the conceptual model development, testing, and refinement processes. The book examines fluid flow and transport mechanisms, noting the difficulty of modeling solute transport, and identifies geochemical and environmental tracer data as important components of the modeling process. Finally, the book recommends several areas for continued research.

Dynamics of Fluids in Fractured Rock
Dynamics of Fluids in Fractured Rock

Author: Boris Faybishenko

Publisher: American Geophysical Union

Published: 2000-01-10

Total Pages: 422

ISBN-13:

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Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 122. Among the current problems that hydrogeologists face, perhaps there is none as challenging as the characterization of fractured rock. Within hydrogeological systems, general issues concerning groundwater flow and environmental remediation cannot be resolved in any practical manner prior to investigating the nature and vagaries of the fracture networks themselves. Comparable difficulties arise when developing economic programs for the exploitation of oil, gas, and geothermal reservoirs in fractured rock. Equal, if not greater, difficulties have commanded our attention relatively recently in regard to the storing of spent fuel generated by nuclear power plants. For example, if we are to isolate spent nuclear fuel in underground rock systems, we must construct a repository to protect the biosphere from contamination by radioactivity while subjecting the total rock system to a significant thermal field for many thousands of years. Predicting the behavior of a waste repository under such conditions, especially in fractured rock, is a formidable task.

Flow and Transport Through Unsaturated Fractured Rock
Flow and Transport Through Unsaturated Fractured Rock

Author: Daniel D. Evans

Publisher: American Geophysical Union

Published: 2001-01-09

Total Pages: 212

ISBN-13:

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Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 42. This monograph is an update and revision of the first edition, Geophysical Monograph 42, on ground-water flow and transport through unsaturated, fractured rock, published by AGU in 1987. The first edition evolved from a special symposium held during the American Geophysical Union fall meetings in San Francisco in December 1986. Invited and contributed papers at that AGU session, as well as panel presentations, focused on conceptualizing, measuring and modeling flow and transport through unsaturated fractured rock. As noted in the preface to the first edition, "the expanded interest in the topic (water flow and contaminant transport through unsaturated fractured rock) was initiated when the U.S. Geological Survey proposed that deep unsaturated zones in arid regions be considered in the site selection for the first high-level, commercially generated radioactive waste repository." Much of the research reported in that first edition was motivated by the U.S. Department of Energy's program to investigate Yucca Mountain at the Nevada Test Site as a possible geologic repository for commercially generated, high-level radioactive waste. As noted in the overview paper of the first edition, "characterization methods and modeling are in their developmental stage with the greatest lack of knowledge being the interaction between fracture and matrix flow and transport properties." Although the first edition of this monograph reflected the state-of-the science, laboratory and field experimental programs were novel and limited and, in general, followed from the principles and methods developed in the soil science community.

Fluid Dynamics in Complex Fractured-Porous Systems
Fluid Dynamics in Complex Fractured-Porous Systems

Author: Boris Faybishenko

Publisher: John Wiley & Sons

Published: 2015-06-04

Total Pages: 265

ISBN-13: 1118877284

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Despite of many years of studies, predicting fluid flow, heat, and chemical transport in fractured-porous media remains a challenge for scientists and engineers worldwide. This monograph is the third in a series on the dynamics of fluids and transport in fractured rock published by the American Geophysical Union (Geophysical Monograph Series, Vol. 162, 2005; and Geophysical Monograph, No. 122, 2000). This monograph is dedicated to the late Dr. Paul Witherspoon for his seminal influence on the development of ideas and methodologies and the birth of contemporary fractured rock hydrogeology, including such fundamental and applied problems as environmental remediation; exploitation of oil, gas, and geothermal resources; disposal of spent nuclear fuel; and geotechnical engineering. This monograph addresses fundamental and applied scientific questions and is intended to assist scientists and practitioners bridge gaps in the current scientific knowledge in the areas of theoretical fluids dynamics, field measurements, and experiments for different practical applications. Readers of this book will include researchers, engineers, and professionals within academia, Federal agencies, and industry, as well as graduate/undergraduate students involved in theoretical, experimental, and numerical modeling studies of fluid dynamics and reactive chemical transport in the unsaturated and saturated zones, including studies pertaining to petroleum and geothermal reservoirs, environmental management and remediation, mining, gas storage, and radioactive waste isolation in underground repositories. Volume highlights include discussions of the following: Fundamentals of using a complex systems approach to describe flow and transport in fractured-porous media. Methods of Field Measurements and Experiments Collective behavior and emergent properties of complex fractured rock systems Connection to the surrounding environment Multi-disciplinary research for different applications