Unsaturated Zone Hydrology

✍ Scribed by Gary L. Guymon

• Publisher: Pearson Technology Group
• Year: 2008
• Tongue: English
• Leaves: 225
• Category: Library

✦ Synopsis

Using a quantitative modeling approach, this volume offers a comprehensive exploration of the movement of water in the unsaturated zone (and associated transport phenomena) – the pathway of many contaminants to the saturated zone where much of the world's potable water is stored. It is the first book to combine research and knowledge on this subject from a wide variety of disciplines into a single source directed toward engineering and environmental training and applications. Deals with contaminant and heat transport in the unsaturated zone; includes a description of soils and their properties and unsaturated soil hydraulic properties; describes unsaturated zone processes; and thoroughly explores numerical modeling and uncertainty in modeling. A text for students in engineering and environmental science, and a reference for practicing engineers and scientists involved in the analysis of unsaturated zone contaminant problems.

✦ Table of Contents

CONTENTS
1 INTRODUCTION
1.1 Unsaturated Zone in the Hydrologic Cycle
1.1.1 The Hydrologic Cycle
1.1.2 Classification of Subsurface Water
1.2 Modeling Concepts
1.2.1 Modeling Steps
1.2.2 Continuum Approach
1.2.3 Uncertainty in Modeling
2 SOILS
2.1 Geologic Origin of Soils
2.1.1 Rock Types
2.1.2 Residual Deposits
2.1.3 Alluvial Deposits
2.1.4 Lacustrine Deposits
2.1.5 Marine Deposits
2.1.6 Aeolian Deposits
2.1.7 Organic Deposits
2.1.8 Glacial Deposits
2.2 Soil Solution
2.2.1 Phases and Components
2.2.2 Liquid Phase
2.2.3 Gaseous Phase
2.2.4 Solid Phase
2.3 Solid Matrix
2.3.1 Soil as a Porous Medium
2.3.2 Clays and Soil Minerals
2.3.3 Microstructure
2.3.4 Macrostructure
2.3.5 Heterogeneity and Anisotropy
2.4 Measures and Classifications of Soil
2.4.1 Particle Size
2.4.2 Specific Surface Area
2.4.3 Porosity and Void Ratio
2.4.4 Soil Density
2.4.5 Fluid Content
2.4.6 Textural Classification of Soils
2.4.7 Unified Soil Classification
2.4.8 Chemical Classifications
3 ENERGY STATES AND GRADIENTS
3.1 Kinds of Energy
3.1.1 Mechanical Energy
3.1.2 Chemical Energy
3.1.3 Thermal Energy
3.1.4 Electrical Energy
3.1.5 Internal Energy
3.1.6 Total Energy
3.2 Pore-Water Pressure
3.2.1 Soil-Water Surface Energy
3.2.2 Capillary Pressure
3.2.3 Total Pore-Water Pressure
3.3 Retension Relationships (Soil Water Characteristics)
3.3.1 Retention Curves
3.3.2 Hysteresis
3.3.3 Emperical Estimation Techniques
3.4 Gradients
3.4.1 Multiple Gradients
3.4.2 Gradient Vectors
3.4.3 Hydraulic Gradient
3.4.4 Temperature Gradient
3.4.5 Chemical Gradient
4 FLOW AND TRANSPORT LAWS
4.1 Darcy's Law
4.1.1 Saturated Flow
4.1.2 Unsaturated Flow
4.1.3 Hysteresis
4.1.4 Empirical Techniques for Determining Hydraulic Conductivity
4.2 Fick's Law and Dispersion
4.2.1 Molecular Diffusion
4.2.2 Dispersion
4.2.3 Total Dispersion Transport
4.3 Fourier's Law
4.3.1 Conducted Heat for a Single Material
4.3.2 Thermal Conductivity
4.3.3 Conducted Heat for Multicomponent Systems
5 UNSATURATED ZONE BEHAVIOR
5.1 Moisture in Unsaturated Zone Components
5.1.1 The Land Surface Boundary
5.1.2 The Root Zone as a Lumped System
5.1.3 The Intermediate Zone
5.1.4 The Capillary Zone
5.1.5 The Water Table
5.2 Methods of Visualizing Data
5.2.1 State Variable Versus Depth Plots
5.2.2 Depth Versus Time Plots
5.2.3 Total Hydraulic Head Plots
5.3 Infiltration
5.3.1 Influence of Soil Structure
5.3.2 Vertical Infiltration Into Dry Soil
5.3.3 Infiltration Through a Less Permeable Strata
5.3.4 Infiltration From Ponds
5.4 Wetting Soil Profile
5.4.1 Moisture Redistribution During Rainfall or Applied Water
5.4.2 Wetting Front Advance
5.4.3 Rising Water Table
5.5 Draining Soil Profile
5.5.1 Evaporation
5.5.2 Drainage of an Initially Wet Soil
5.5.3 Falling Water Table
5.6 Movement of Miscible Compounds in the Soil Profile
5.6.1 Miscible Compound Advance
5.6.2 Leaching
5.6.3 Breakthrough Curves
5.6.4 Lumped Time-of-Travel Model
5.7 Heat Transport in the Soil Profile
5.7.1 Thermal Energy Balance for the Land Surface
5.7.2 Latent Heat Effects
5.7.3 Temperature Profiles
5.8 Air Movement in the Soil Profile
5.8.1 Boundary Effects
5.8.2 Wetting and Drying Effects
6 EQUATIONS OF ISOTHERMAL FLOW
6.1 Continuity
6.1.1 Conservation of Mass
6.1.2 Nondeformable Differential Element
6.1.3 Continuity
6.1.4 Sources and Sinks
6.2 Isothermal flow Equations
6.2.1 In Terms of Total Hydraulic Head
6.2.2 In Terms of Pressure Head
6.2.3 In Terms of Water Content
6.3 Auxiliary Conditions
6.3.1 Initial Conditions
6.3.2 Boundary Conditions
6.4 The Complete Mathematical Model
6.5 Dual Porosity Systems
6.5.1 Nature of the Problem
6.5.2 Lumped Dual Porosity Models
6.6 Analytical Solutions
7 TRANSPORT OF DISSOLVED COMPOUNDS
7.1 Mass Transport Processes
7.1.1 Advection
7.1.2 Hydrodynamic Dispersion
7.1.3 Sorption and Retardation
7.1.4 Chemical Transformation
7.1.5 Volatilization
7.2 Transport Equation
7.2.1 Transport Equation for a Single Nonreacting Species
7.2.2 Inclusion of Sources and Sinks
7.2.3 Coupling
7.2.4 Limitations
7.3 Auxiliary Conditions
7.3.1 Initial Conditions
7.3.2 Boundary Conditions
7.4 Transfer Function Models
7.5 The Complete Mathematical Model
7.6 Analytical Solution
8 HEAT TRANSPORT
8.1 Heat Transport Process
8.1.1 Heat Capacity
8.1.2 Change of Phase
8.1.3 Conduction
8.1.4 Advection
8.2 Heat Transport Equation
8.2.1 Energy Balance
8.2.2 Heat Transport
8.3 Auxiliary Conditions
8.3.1 Initial Conditions
8.3.2 Boundary Condition
8.4 The Complete Mathematical Model
9 NUMERICAL METHODS
9.1 Introduction
9.1.1 Overview of Methods
9.1.2 Need to Discretize
9.1.3 Numerical Modeling Procedure
9.2 Finite Differences
9.2.1 Approximation of Flow Equation
9.2.2 Stability and Convergence
9.2.3 Implicit Solutions
9.2.4 Boundary Conditions
9.2.5 Algorithm Strategies
9.2.6 Approximation of Nonsymmetrical Equations
9.3 Finite Elements
9.3.1 Approximation of Flow Equations
9.3.2 Stability and Convergence
9.3.3 Boundary Conditions
9.3.4 Algorithm Strategies
9.3.5 Approximation of Nonsymmetrical Equations
9.4 Domain Methods
10 MODEL UNCERTAINTY
10.1 Sources of Uncertainty
10.1.1 Conceptualization
10.1.2 Numerical Solutions
10.1.3 Auxiliary Conditions
10.1.4 Parameters
10.2 Elementary Statistics
10.2.1 Sample Statistics
10.3 Probability and Distributions
10.3.1 Probability Distribution Functions
10.3.2 Confidence Limits
10.4 Analysis of Uncertainty
10.4.1 Modeling concepts
10.4.2 Monte Carlo Technique
10.4.3 Two-Point Technique
A: MEASUREMENT METHODS AND EQUIPMENT
A.1 Water Content
A.2 Pore-Water Pressure
A.3 Retention Curves
A.4 Unsaturated Hydraulic Conductivity
A.5 Soil Water Chemistry
A.6 Soil Temperature
B: PHYSICAL PROPERTIES OF WATER AND AIR
C: SELECTED CONVERSION FACTORS
INDEX
A
B
C
D
E
F
G
H
I
L
M
N
O
P
R
S
T
U
V
W
Z