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Welcome to Welcome to BRE542!BRE542!
Vadose ZoneVadose Zone TransportTransport
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TodayTodayIntroduction to CourseIntroduction to CourseRelated TextsRelated TextsDefinition/importance of Vadose Definition/importance of Vadose
ZoneZoneRelated areas of studyRelated areas of studyHistory of Investigation of Vadose History of Investigation of Vadose
ProcessesProcessesRelationship to Saturated MediaRelationship to Saturated Media
Introduction to CourseIntroduction to CourseRelated TextsRelated TextsDefinition/importance of Vadose Definition/importance of Vadose
ZoneZoneRelated areas of studyRelated areas of studyHistory of Investigation of Vadose History of Investigation of Vadose
ProcessesProcessesRelationship to Saturated MediaRelationship to Saturated Media
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Logistical IssuesLogistical IssuesBRE 542, Vadose Zone Transport, Fall 2003 Department of BioengineeringJohn S. SelkerTelephone: 541-737-6304 email: [email protected] hours: MWF 10am-11am, or by appointmentLab help hours: Monday 4:00-4:45Websites:
Vadose kits: http://bre.orst.edu/faculty/selker/vadose_teaching.aspLectures: http://bre.orst.edu/vzp
How the BRE 542 will be run•Three exciting lectures/wk•Numerical simulation project (you don’t need to write code)Homework largely from experiments•Experimental and data-based homework.
BRE 542, Vadose Zone Transport, Fall 2003 Department of BioengineeringJohn S. SelkerTelephone: 541-737-6304 email: [email protected] hours: MWF 10am-11am, or by appointmentLab help hours: Monday 4:00-4:45Websites:
Vadose kits: http://bre.orst.edu/faculty/selker/vadose_teaching.aspLectures: http://bre.orst.edu/vzp
How the BRE 542 will be run•Three exciting lectures/wk•Numerical simulation project (you don’t need to write code)Homework largely from experiments•Experimental and data-based homework.
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More Logistics ... GradingMore Logistics ... Grading
• One homework per week given on Monday, due the following Monday by 5 PM. (1/2 grade).
• One numerical modeling project (presentation plus 7 page paper; 1/6 of grade). Papers are due Dec 5. See special handout on this component.
• 10 min quizzes will be carried out after each of the 4 chapters, announced 1 week in advance (1/6 of grade).
• Final exam (1/6th of grade). A closed book exam which covers the most significant concepts presented in the course.
• One homework per week given on Monday, due the following Monday by 5 PM. (1/2 grade).
• One numerical modeling project (presentation plus 7 page paper; 1/6 of grade). Papers are due Dec 5. See special handout on this component.
• 10 min quizzes will be carried out after each of the 4 chapters, announced 1 week in advance (1/6 of grade).
• Final exam (1/6th of grade). A closed book exam which covers the most significant concepts presented in the course.
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Idiosyncrasies in the professor (the fine print)Idiosyncrasies in the professor (the fine print)
Interpretation: 25% of the score of each problem is given for interpretation of the result (qualitative)
Calculations: Even if you have the right number written down for the answer, you are only 75% of the way done unless you have thought about what the results mean.
Late homework is not accepted unless prior arrangements have been made, as homework is often handed back on the next class meeting.
The Rules:
Group work: Wonderful, but must list the group of helpers, and may not simply copy the work of others.
Writing: must be your own work, unless properly cited. If in doubt, ask me. Plagiarism of written work will result in failing the course.
Interpretation: 25% of the score of each problem is given for interpretation of the result (qualitative)
Calculations: Even if you have the right number written down for the answer, you are only 75% of the way done unless you have thought about what the results mean.
Late homework is not accepted unless prior arrangements have been made, as homework is often handed back on the next class meeting.
The Rules:
Group work: Wonderful, but must list the group of helpers, and may not simply copy the work of others.
Writing: must be your own work, unless properly cited. If in doubt, ask me. Plagiarism of written work will result in failing the course.
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Course OutlineCourse Outline1. An Introduction to the Vadose Zone (4 lect.)
• History of investigation
• Modern concerns
• Relationship to saturated media
• Primer on soils
2. Physical & Hydraulic Properties Unsaturated Media (8 lect)
• Basic definitions
• Hydrostatics (Surface tension;Characteristic curves; Hysteresis)
• Hydrodynamics in porous media (Darcy's law; Richards equation)
3. Flow of Water in the Vadose Zone (10 lect.)
• The classic solutions (Green & Ampt; Evaporation from Water Table).
• Solution for capillary barriers
• Miller and Miller scaling
• Characterization of soil hydraulic properties
1. An Introduction to the Vadose Zone (4 lect.)
• History of investigation
• Modern concerns
• Relationship to saturated media
• Primer on soils
2. Physical & Hydraulic Properties Unsaturated Media (8 lect)
• Basic definitions
• Hydrostatics (Surface tension;Characteristic curves; Hysteresis)
• Hydrodynamics in porous media (Darcy's law; Richards equation)
3. Flow of Water in the Vadose Zone (10 lect.)
• The classic solutions (Green & Ampt; Evaporation from Water Table).
• Solution for capillary barriers
• Miller and Miller scaling
• Characterization of soil hydraulic properties
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Course Outline ContinuedCourse Outline Continued4. Solute Transport in the Vadose Zone (5 lect.)
•Processes - Advection, adsorption, diffusion, degradation. • Advective Diffusive Equation (Linearity, superposition, solutions).
5. Three-phase flow (2 lect.)• Surface tension, spreading pressure, layered menisci• Constitutive relations: Pressure-Saturation-Permeability• Funicular and residual saturation• Special problems with continuum assumptions: non-spreading oil.
6. Special Processes (2 lect.)• Macropore Flow• Fingered Flow• Biological considerations
4. Solute Transport in the Vadose Zone (5 lect.)•Processes - Advection, adsorption, diffusion, degradation. • Advective Diffusive Equation (Linearity, superposition, solutions).
5. Three-phase flow (2 lect.)• Surface tension, spreading pressure, layered menisci• Constitutive relations: Pressure-Saturation-Permeability• Funicular and residual saturation• Special problems with continuum assumptions: non-spreading oil.
6. Special Processes (2 lect.)• Macropore Flow• Fingered Flow• Biological considerations
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The Numerical Component of BRE542The Numerical Component of BRE542
Software Description and Access The software is called HYDRUS-2D
Developed by the staff of the US salinity lab in riverside CA.
Windows based modules with excellent graphical interface.
The users manual is very technical
4:00-4:45 PM help sessions Gilmore annex on Mondays.
The computer in the upstairs of the annex is set up with new HP workstations – they rip!
You may use the computers on a first come first served basis at other unscheduled times.
No machines should be left running over night in order to maintain access for other students.
Software Description and Access The software is called HYDRUS-2D
Developed by the staff of the US salinity lab in riverside CA.
Windows based modules with excellent graphical interface.
The users manual is very technical
4:00-4:45 PM help sessions Gilmore annex on Mondays.
The computer in the upstairs of the annex is set up with new HP workstations – they rip!
You may use the computers on a first come first served basis at other unscheduled times.
No machines should be left running over night in order to maintain access for other students.
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The Numerical Component of BRE542The Numerical Component of BRE542
1. 1. Learning the interfaceLearning the interface A.A. Clicking through the menus and printing resultsClicking through the menus and printing resultsB. B. Setting up a problem from scratch.Setting up a problem from scratch.
2. Running a simple problem2. Running a simple problemDraining a profile from saturation to hydrostatic.Draining a profile from saturation to hydrostatic.
3. Project3. Project
Rules for numerical homeworkRules for numerical homework Do all the key strokes for your problem with your own hands, but may talk
to others and watch others do their problems as much as you like. Start a problem using the files indicated in the homework (either ones
prepared by me, or new files). Only you can enter data in your problem. If you want help from a friend,
they can show you by going through operations on their files.
1. 1. Learning the interfaceLearning the interface A.A. Clicking through the menus and printing resultsClicking through the menus and printing resultsB. B. Setting up a problem from scratch.Setting up a problem from scratch.
2. Running a simple problem2. Running a simple problemDraining a profile from saturation to hydrostatic.Draining a profile from saturation to hydrostatic.
3. Project3. Project
Rules for numerical homeworkRules for numerical homework Do all the key strokes for your problem with your own hands, but may talk
to others and watch others do their problems as much as you like. Start a problem using the files indicated in the homework (either ones
prepared by me, or new files). Only you can enter data in your problem. If you want help from a friend,
they can show you by going through operations on their files.
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¡El Proyecto!¡El Proyecto!Project is 1/6 of the grade for the course.
Phase 1. Defining the problem.a. Due October 3 (15%). 1 or 2 page statement of problem importance, boundary conditions, and expected outcome.b. Due October 13 (15%). Layout of problem in HYDRUS-2D. Define in detail the full problem to be solved
Phase 2. Initial simulation results Oct 31 (20%). Write up (1-3 pg text plus figures).
Phase 3. Presentations. November 24 and 25 (25%). 7:00-9:30 evening donut and coffee evening sessions of 12 minute presentations. Must come to both sessions.
Phase 4. Final submission Dec 5. <10pgs + figures.
Project is 1/6 of the grade for the course.Phase 1. Defining the problem.
a. Due October 3 (15%). 1 or 2 page statement of problem importance, boundary conditions, and expected outcome.b. Due October 13 (15%). Layout of problem in HYDRUS-2D. Define in detail the full problem to be solved
Phase 2. Initial simulation results Oct 31 (20%). Write up (1-3 pg text plus figures).
Phase 3. Presentations. November 24 and 25 (25%). 7:00-9:30 evening donut and coffee evening sessions of 12 minute presentations. Must come to both sessions.
Phase 4. Final submission Dec 5. <10pgs + figures.
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Drivers, start Drivers, start your engines!your engines!
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Disciplinary ContextDisciplinary Context
Related Texts
Definition/importance of Vadose Zone
Related areas of study
Related Texts
Definition/importance of Vadose Zone
Related areas of study
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HISTORY OF INVESTIGATIONHISTORY OF INVESTIGATION
It’s worthwhile to understand the It’s worthwhile to understand the historical context of the study of historical context of the study of unsaturated flow:unsaturated flow:
A young field with ongoing conceptual A young field with ongoing conceptual developmentdevelopment
Provides a preview of the topics covered Provides a preview of the topics covered in the coursein the course
It’s worthwhile to understand the It’s worthwhile to understand the historical context of the study of historical context of the study of unsaturated flow:unsaturated flow:
A young field with ongoing conceptual A young field with ongoing conceptual developmentdevelopment
Provides a preview of the topics covered Provides a preview of the topics covered in the coursein the course
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Evidence of ancient operational Evidence of ancient operational understanding of hydrologyunderstanding of hydrology
Ancient qanats of AdenAncient qanats of AdenMarib dam in Yemen built in 500 b.c. Marib dam in Yemen built in 500 b.c.
and lasting to the beginning of alternate and lasting to the beginning of alternate routes through the orient around 500 routes through the orient around 500 a.d. 600 meter face supporting a.d. 600 meter face supporting agriculture for 100,000 people.agriculture for 100,000 people.
600 a.d. Sri Lanka builds a network of 600 a.d. Sri Lanka builds a network of irrigation works that survive to this day.irrigation works that survive to this day.
Yet I know of no evidence that the underlying Yet I know of no evidence that the underlying quantitative relationships between soil type, pressure quantitative relationships between soil type, pressure and flow were understood.and flow were understood.
Ancient qanats of AdenAncient qanats of AdenMarib dam in Yemen built in 500 b.c. Marib dam in Yemen built in 500 b.c.
and lasting to the beginning of alternate and lasting to the beginning of alternate routes through the orient around 500 routes through the orient around 500 a.d. 600 meter face supporting a.d. 600 meter face supporting agriculture for 100,000 people.agriculture for 100,000 people.
600 a.d. Sri Lanka builds a network of 600 a.d. Sri Lanka builds a network of irrigation works that survive to this day.irrigation works that survive to this day.
Yet I know of no evidence that the underlying Yet I know of no evidence that the underlying quantitative relationships between soil type, pressure quantitative relationships between soil type, pressure and flow were understood.and flow were understood.
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Review: First quantitative Review: First quantitative understanding of saturated flow understanding of saturated flow Darcy 1856 study of the Darcy 1856 study of the
aquifers under Dijon; aquifers under Dijon; Introduced the concept of Introduced the concept of potential flowpotential flow
Water moves in direct proportion to:Water moves in direct proportion to:
the gradient of potential energythe gradient of potential energy
the permeability of the mediathe permeability of the media
Darcy 1856 study of the Darcy 1856 study of the aquifers under Dijon; aquifers under Dijon; Introduced the concept of Introduced the concept of potential flowpotential flow
Water moves in direct proportion to:Water moves in direct proportion to:
the gradient of potential energythe gradient of potential energy
the permeability of the mediathe permeability of the media
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First quantitative application to First quantitative application to unsaturated flowunsaturated flow
1870’s Bousinesq extended Darcy’s 1870’s Bousinesq extended Darcy’s law with two approximations (Dupiut-law with two approximations (Dupiut-Forcheimer) to deal with drainage and Forcheimer) to deal with drainage and filling of media.filling of media.
““Free water surface” problems. Free water surface” problems. Useful solutions for dikes land Useful solutions for dikes land
drainage, etc. (all as a footnote drainage, etc. (all as a footnote in his book)in his book)
Bousinesq equation is strongly Bousinesq equation is strongly nonlinear: much tougher to solve! nonlinear: much tougher to solve!
1870’s Bousinesq extended Darcy’s 1870’s Bousinesq extended Darcy’s law with two approximations (Dupiut-law with two approximations (Dupiut-Forcheimer) to deal with drainage and Forcheimer) to deal with drainage and filling of media.filling of media.
““Free water surface” problems. Free water surface” problems. Useful solutions for dikes land Useful solutions for dikes land
drainage, etc. (all as a footnote drainage, etc. (all as a footnote in his book)in his book)
Bousinesq equation is strongly Bousinesq equation is strongly nonlinear: much tougher to solve! nonlinear: much tougher to solve!
Bousinesq
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Rigorous foundation for Rigorous foundation for Darcy’s LawDarcy’s Law
First encyclopedic source of practical First encyclopedic source of practical solutions based on pore-scale analysissolutions based on pore-scale analysis
1899 Slichter “Theory of Flow Through 1899 Slichter “Theory of Flow Through Porous Media”Porous Media”
Exact solutions for multiple pumped wellsExact solutions for multiple pumped wells
Basis of aquifer testing.Basis of aquifer testing.
First encyclopedic source of practical First encyclopedic source of practical solutions based on pore-scale analysissolutions based on pore-scale analysis
1899 Slichter “Theory of Flow Through 1899 Slichter “Theory of Flow Through Porous Media”Porous Media”
Exact solutions for multiple pumped wellsExact solutions for multiple pumped wells
Basis of aquifer testing.Basis of aquifer testing.
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Slichter – some of his figuresSlichter – some of his figures
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Extension of Darcy’s Law to Extension of Darcy’s Law to Unsaturated ConditionsUnsaturated Conditions
1907 Buckingham (of Buckingham-pi 1907 Buckingham (of Buckingham-pi fame) Darcy for steady flow with:fame) Darcy for steady flow with:
Conductivity a function of moisture contentConductivity a function of moisture content
Potential includes capillary pressures Potential includes capillary pressures
1907 Buckingham (of Buckingham-pi 1907 Buckingham (of Buckingham-pi fame) Darcy for steady flow with:fame) Darcy for steady flow with:
Conductivity a function of moisture contentConductivity a function of moisture content
Potential includes capillary pressures Potential includes capillary pressures
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Extension of Darcy’s Law Extension of Darcy’s Law (cont.)(cont.)
Rule: Folks who write equations Rule: Folks who write equations are remembered for eternity, are remembered for eternity, while the poor work-a-days who while the poor work-a-days who solve them are quickly forgotten. solve them are quickly forgotten.
Exception: Green and Ampt, Exception: Green and Ampt, 1911. Key problem of infiltration.1911. Key problem of infiltration.
Modeled as a capillary tubes which Modeled as a capillary tubes which filled in parallel, from dry to saturation.filled in parallel, from dry to saturation.
Still most widely used infiltration Still most widely used infiltration model.model.
Rule: Folks who write equations Rule: Folks who write equations are remembered for eternity, are remembered for eternity, while the poor work-a-days who while the poor work-a-days who solve them are quickly forgotten. solve them are quickly forgotten.
Exception: Green and Ampt, Exception: Green and Ampt, 1911. Key problem of infiltration.1911. Key problem of infiltration.
Modeled as a capillary tubes which Modeled as a capillary tubes which filled in parallel, from dry to saturation.filled in parallel, from dry to saturation.
Still most widely used infiltration Still most widely used infiltration model.model.
d
L
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Time passes...time passes Time passes...time passes We need a few tools!!We need a few tools!!
Early 1920’s, W. Gardner’s lab develop the Early 1920’s, W. Gardner’s lab develop the tensiometer: direct measurement of the capillary tensiometer: direct measurement of the capillary pressurepressure
L.A. Richards extended idea to tension plate: measure L.A. Richards extended idea to tension plate: measure moisture content as a function of capillary pressuremoisture content as a function of capillary pressure
And then...And then...
1931, Richards derived equation for unsaturated flow. 1931, Richards derived equation for unsaturated flow. (p.s. Richards just died in the last 5 years).(p.s. Richards just died in the last 5 years).
Early 1920’s, W. Gardner’s lab develop the Early 1920’s, W. Gardner’s lab develop the tensiometer: direct measurement of the capillary tensiometer: direct measurement of the capillary pressurepressure
L.A. Richards extended idea to tension plate: measure L.A. Richards extended idea to tension plate: measure moisture content as a function of capillary pressuremoisture content as a function of capillary pressure
And then...And then...
1931, Richards derived equation for unsaturated flow. 1931, Richards derived equation for unsaturated flow. (p.s. Richards just died in the last 5 years).(p.s. Richards just died in the last 5 years).
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Moisture contents depends on Moisture contents depends on history of wettinghistory of wetting
Haines (1930) wetting Haines (1930) wetting proceeds as “jumps”proceeds as “jumps”
Still largely ignored, but Still largely ignored, but essential to unsaturated essential to unsaturated flow processes.flow processes.
Haines (1930) wetting Haines (1930) wetting proceeds as “jumps”proceeds as “jumps”
Still largely ignored, but Still largely ignored, but essential to unsaturated essential to unsaturated flow processes.flow processes.
Soil
Porous Plate
r1
2r2
stage 1 stages 2 and 3
stages 4 and 5 stages 6 and 7
-2r 2
-2r 1
Moisture Content sat0
0 r
(2)
(5)
(6)
(7)
(4)
(1)
(3)
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Time passes ... time passesTime passes ... time passesTurns out that Richards equation is a bear to solve! Turns out that Richards equation is a bear to solve! Depends on three non-linear variables: q, y, K Depends on three non-linear variables: q, y, K
First big break for R’s Eq.First big break for R’s Eq.
1952, Klute rewrote Richards equation in terms of 1952, Klute rewrote Richards equation in terms of moisture content alonemoisture content alonediffusion equation (AKA: Fokker-Plank eq.)diffusion equation (AKA: Fokker-Plank eq.)
Klute gave solution to 1-D capillary infiltrationKlute gave solution to 1-D capillary infiltration
Turns out that Richards equation is a bear to solve! Turns out that Richards equation is a bear to solve! Depends on three non-linear variables: q, y, K Depends on three non-linear variables: q, y, K
First big break for R’s Eq.First big break for R’s Eq.
1952, Klute rewrote Richards equation in terms of 1952, Klute rewrote Richards equation in terms of moisture content alonemoisture content alonediffusion equation (AKA: Fokker-Plank eq.)diffusion equation (AKA: Fokker-Plank eq.)
Klute gave solution to 1-D capillary infiltrationKlute gave solution to 1-D capillary infiltration
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Analytical vs. NumericalAnalytical vs. Numerical
Since 1952, more analytical solutions have Since 1952, more analytical solutions have been presented, BUT non-linearity limited to been presented, BUT non-linearity limited to special conditions.special conditions.
What is the use of Analytical results?What is the use of Analytical results?They let you see the implications of the physical They let you see the implications of the physical
parameters parameters
computers allow solution of individual problems: computers allow solution of individual problems: tough to generalizetough to generalize
Since 1952, more analytical solutions have Since 1952, more analytical solutions have been presented, BUT non-linearity limited to been presented, BUT non-linearity limited to special conditions.special conditions.
What is the use of Analytical results?What is the use of Analytical results?They let you see the implications of the physical They let you see the implications of the physical
parameters parameters
computers allow solution of individual problems: computers allow solution of individual problems: tough to generalizetough to generalize
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Then things took off! Then things took off!
Lots of great stuff in the 50’s and early Lots of great stuff in the 50’s and early 60’s60’s1956: Miller and Miller: relationship of 1956: Miller and Miller: relationship of
grain size to fluid propertiesgrain size to fluid properties
Lots of great stuff in the 50’s and early Lots of great stuff in the 50’s and early 60’s60’s1956: Miller and Miller: relationship of 1956: Miller and Miller: relationship of
grain size to fluid propertiesgrain size to fluid properties
Degree of Saturation
Mat
ric
Pot
enti
al (
cm H
2O)
0
10
20
30
40
50
60
70
80
0 0.2 0.4 0.6 0.8 1
12/20
20/30
30/40
40/50
Degree of Saturation
Sca
led
Pot
enti
al
0
10
20
30
40
50
60
0 0.2 0.4 0.6 0.8 1
12/20
20/30
30/40
40/50
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More 50’s and 60’sMore 50’s and 60’s
1957: Philip start to deal with infiltration1957: Philip start to deal with infiltration
1962: Poulovassilis: independent 1962: Poulovassilis: independent domain model of hysteresis (finally domain model of hysteresis (finally Haines stuff can be included)Haines stuff can be included)
1957: Philip start to deal with infiltration1957: Philip start to deal with infiltration
1962: Poulovassilis: independent 1962: Poulovassilis: independent domain model of hysteresis (finally domain model of hysteresis (finally Haines stuff can be included)Haines stuff can be included)
h
(Fill
ing
Pressu
re)
00
h (Emptying Pressure)
e
f
45o
f
(Fra
ctio
n of
Moi
stur
e C
onte
nt)
he h +he e
hf
h +hf f
27
1970’s: limitations of the 1970’s: limitations of the assumptions assumptions
Biggar & Nielson (1970)Biggar & Nielson (1970) field scale heterogeneity field scale heterogeneity
Hill & Parlange (1972)Hill & Parlange (1972)fingered flow fingered flow
Others: Others: macroporesmacroporesKung (1988): Funnel FlowKung (1988): Funnel Flow
Biggar & Nielson (1970)Biggar & Nielson (1970) field scale heterogeneity field scale heterogeneity
Hill & Parlange (1972)Hill & Parlange (1972)fingered flow fingered flow
Others: Others: macroporesmacroporesKung (1988): Funnel FlowKung (1988): Funnel Flow
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Relationship to saturated mediaRelationship to saturated media
While the similarity has been very useful, it While the similarity has been very useful, it is a source of many errors is a source of many errors
Main distinctions in three areas. Main distinctions in three areas. Capillarity (lateral, upward flow)Capillarity (lateral, upward flow)Heterogeneity into the temporal domainHeterogeneity into the temporal domainBiochemical activityBiochemical activity
Diffusion is two orders of magnitude fasterDiffusion is two orders of magnitude fasterAmple oxygenAmple oxygen
Take-home message: be very careful!Take-home message: be very careful!
While the similarity has been very useful, it While the similarity has been very useful, it is a source of many errors is a source of many errors
Main distinctions in three areas. Main distinctions in three areas. Capillarity (lateral, upward flow)Capillarity (lateral, upward flow)Heterogeneity into the temporal domainHeterogeneity into the temporal domainBiochemical activityBiochemical activity
Diffusion is two orders of magnitude fasterDiffusion is two orders of magnitude fasterAmple oxygenAmple oxygen
Take-home message: be very careful!Take-home message: be very careful!
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Issue Vadose Zone Saturated ZoneConductivity at apoint
A nonlinear function ofmoisture content.
Constant.
Density Effects Negligible influence fortemperature and solutebased changes.
Temperature and solutebased density differences candominate both static anddynamic disposition.
Spatial variability Lognormal distributionand a function of moisturecontent and hence time.
Lognormal distribution fixedin time.
Biological andchemical activity
Often high in carbon andoxygen, leading to rapidmicrobial metabolism.
Typically anoxic with sparsecarbon: comparatively slowmicrobial activity.
Transportmechanisms
Advection 0-10 cm/dayDispersivity 0.5-20 cmDiffusion 0.1-.3 cm2/s
Advection 0-100 cm/dayDispersivity 0.5-20 cmDiffusion 0.00002 cm2/s
Similarities:• Both have governing equations for flow that are
linear in the local potential gradient• They share similar constitutive media (with
particles ranging from clay to gravel)
Differences
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Contemporary Concerns with Contemporary Concerns with the Vadose Zonethe Vadose Zone
Water conservation (how to use minimum Water conservation (how to use minimum water to irrigate crops)water to irrigate crops)
Nutrient storage and transportNutrient storage and transportPesticide degradation and movementPesticide degradation and movementSalinity controlSalinity controlWater budget for climatic modelingWater budget for climatic modelingBulk petroleum and organic contaminant Bulk petroleum and organic contaminant
transport (vapor and liquid): Industrial transport (vapor and liquid): Industrial contaminationcontamination
Water conservation (how to use minimum Water conservation (how to use minimum water to irrigate crops)water to irrigate crops)
Nutrient storage and transportNutrient storage and transportPesticide degradation and movementPesticide degradation and movementSalinity controlSalinity controlWater budget for climatic modelingWater budget for climatic modelingBulk petroleum and organic contaminant Bulk petroleum and organic contaminant
transport (vapor and liquid): Industrial transport (vapor and liquid): Industrial contaminationcontamination
31
ExampleExample
Suppose that 2,000 liters of some Suppose that 2,000 liters of some nasty liquid spilled on a 10 mnasty liquid spilled on a 10 m22 area area above an aquifer that was at a depth above an aquifer that was at a depth of 10 m. How much makes it to the of 10 m. How much makes it to the aquifer? aquifer?
Suppose that 2,000 liters of some Suppose that 2,000 liters of some nasty liquid spilled on a 10 mnasty liquid spilled on a 10 m22 area area above an aquifer that was at a depth above an aquifer that was at a depth of 10 m. How much makes it to the of 10 m. How much makes it to the aquifer? aquifer?
