2nd Edition

Soil-Water Interactions Mechanisms Applications, Second Edition, Revised Expanded

By Iwata Copyright 1994

    Emphasizing pioneering achievements, this work offers a clear and systematic description of various soil-water phenomena and their applications to soil problems such as water retention and the flux of water in soils and clays. This second edition contains material on the physical properties of adsorbed water, the application of fractal theory to solute and water flows in field soils, fingering research, and more.

    Preface to Second Edition

    Preface to First Edition

    ENERGY CONCEPT AND THERMODYNAMICS OF WATER IN SOIL

    ENERGY CONCEPT OF WATER IN SOIL

    Historical review of the Energy Concept

    Capillary Potential

    Establishment of the Energy Concept

    Potential of Water in Soil

    Total Potential and Its Components

    Physical Meaning of Tensiometer Pressure

    Difficulties with the Total Potential

    Envelope Pressure Potential or Overburden Potential

    Weakness of the Energy Concept

    THRMODYNAMICS OF WATER IN SOILS

    Thermodynamic Terminology Relating to the Solution Phase in Soil

    Types of Work Relating to Water in Soil

    General Differential Forms of Gibbs Free Energy and Chemical Potential (Total Potential)

    Chemical Potential Water in Soil

    Factors Affecting Chemical Potential

    Variables of State for Water in Soil

    Dependence of Chemical Potential on Position in the Soil Solution

    Chemical Potential as a Driving Force for Liquid Water Flow Under Nonisothermal Conditions

    Temperature Dependence of the Tensiometer Pressure-Water Content Relationship

    Driving Forces

    HYSTERESIS IN SOIL WATER PHENOMENA

    Hysteresis

    Mechanisms for Hysteresis

    Different Pore Sizes

    Adsorbed Water on Clay Surfaces

    Contact Angle

    Theory of Hysteresis Based on the Concept of Domains

    Fundamental Independent Domain Theory

    Application of the Domain Theory to Hysteresis in Soil Water Phenomena

    Further Developments of Domain Theories

    Controversial Points in the Application of the Domain

    Theory to Hysteresis in Soil Water Phenomena

    Other Theories

    Thermodynamics of Systems Exhibiting Hysteresis

    References

    INTERACTION BETWEEN SOIL PARTICLES AND SOIL SOLUTION

    PHYSICAL PROPERTIES OF SUBSTANCES TAKING PART IN INTERACTIONS BETWEEN SOIL SOULTION AND SOIL PARTICLES

    Water

    Structure of the Water Molecule

    Hydrogen Bond

    Structures of Ice and Water

    Hydration of Ions

    Physical and Chemical Properties of Clays

    Structure

    Specific Surface Area

    Electric Charge

    INTERACTION BETWEEN WATER AND AN UNCHARGED SOIL PARTICLE

    DISTRIBUTION OF IONS IN THE NEIGHBORHOOD OF A SOIL PARTICLE

    Balance of Forces on Ions, and the Ionic Distribution

    Gouy Theory

    Infinite Distance Between Plates

    Finite Distance Between Plates

    Unusual Distribution of Electrical Potential Near and Edge Surface of Montmorillonite

    Problems in Application of the Gouy Theory to Clay-Water Systems

    Assumption of Point Charge

    Distribution of Electric Intensities in the Vicinity of a Clay Surface

    Diffuse Layer Terminated by an Air-Water Interface

    Other Factors Neglected in the Gouy Theory

    Force Acting on Water Molecules in a Diffuse Ion Layer

    Significance of the Interaction Between Soil Particles and Soil Solution on Soil Properties

    SOIL FREEZING

    Water-Ice Equilibria

    Chemical Potentials of Water and Ice

    Super-cooling

    Freezing-Point Depression

    Unfrozen Water in Frozen Soils

    Dependence of Unfrozen Water on Original Water Content

    Frost Heaving

    Water Movement in Frost Heaving

    Driving Forces for Water Migration in the Frozen Soil

    Soil Freezing

    Driving Forces at the Freezing Front

    Heaving Pressure

    PHYSICOCHEMICAL PROPERTIES OF ADSORBED WATER

    Preliminary Knowledge Related to Physicochemical Properties of Adsorbed Water

    Physicochemical Properties of Adsorbed Water and Film Thickness

    Distribution of Electric Intensity Near a Clay Surface

    Interaction Between an Ion and Water Molecules

    Interaction Between a Clay Surface and Water Molecules

    Physicochemical Properties of Water Adsorbed by Clays

    Degree of Dissociation of Adsorbed Water

    Interactions Between a Clay Surface and a Water Molecule

    Entropy

    Viscosity

    The Range of Influence for Surface Forces

    References

    INTERACTION BETWEEN PARTICLES THROUGH WATER

    DLVO THEORY

    Potential Energy Due to the Interaction of Two Double Layers

    Repulsive Force Acting Between Two Plates

    Potential Enerfy Due to the Repulsive Force

    Differences Between VRσ and VRψ

    Factor Determining the Repulsive Potential Energy

    Charge-Regulation Model for Particles with Variable Charges

    Potential Energy Due to van der Waals Forces Between Two Particles

    Attraction Energy Due to van der Waals Forces

    Hamaker Constant

    Total Potential Energy

    Other Forces of Interaction Between Charged Surfaces

    Swelling Clays

    Discrete Charges

    Forces Between Mica Surfaces

    Other Surfaces

    TOTAL POTENTIAL ENERGY BETWEEN TWO CLAY PARTICLES

    Montmorillonite

    Repulsion Energy VR

    Attraction Energy VA

    Total Potential Energy VT

    Flocculation of Montmorillonite

    Allophane

    Repulsion Energy VR and Attraction Energy VA

    Total Potential Energy

    Flocculation of Allophane

    SWELLING OF CLAYS

    Crystalline Swelling

    Mechanism of Macroscopic Swelling

    Chemical Potential of Water

    Swelling Under Unsaturated Conditions

    Application of the DLVO Theory to Macroscopic Swelling

    Swelling Theory Based on Structural Forces

    Effect of Clay Dispersion and Swelling on Permeability to Water

    Effect of Electrolyte Concentration

    Effect of pH

    FLOW OF SOLUTIONS THROUGH CLAY LAYERS

    Characteristics of Solution Flow Through Clay Layers

    Salt Sieving and the Salt Sieving or Rejection Coefficient

    Reflection Coefficient or Osmotic Efficiency Coefficient

    Characteristics of Solution Flow Through a Clay Layer

    Theoretical Analyses of Solution Flow Through Clay Layers

    Rejection Coefficient (Salt Sieving Coefficient)

    Streaming Potential

    Relationships Between Factors Influencing Solution Flow Through Clay Layers

    Streaming Potential and Hydraulic Pressure Gradient

    Pressure-Induced and Electrokinetic Flows

    Dependence of Rejection Coefficient on Applied Pressure Gradient and Surface Charge Density

    Application of Irreversible Thermodynamics to Solution Flow Through Clay Layers

    Future Research Effect

    References

     

    CAPILLARY

    AIR WATER INTERFACES

    Laplace Equation

    Capillary Rise in a Tube

    Lens Water Between Spheres

    Meniscus Within a Pore Cell

    Capillary Water in Soils

    Capillary Rise

    Capillary Moisture Distribution Under Suction

    Suspended Capillary Water in Soil

    CAPILLARY THEORY FOR NONUNIFORM CELL SYSTEMS

    Neck Size Distribution Function

    Connecting Systems of Pore Cells

    Drainage Curves

    Capillary Moisture Distribution Curve After Drainage or After Wetting

    References

    WATER FLOW THROUGH SOIL

    GENERAL CONCEPTS OF WATER FLOW

    Historical Review

    Darcy’s Law

    Equation of Continuity

    PRESSURE DISTRIBUTION DURING WATER FLOW

    Steady Vertical Downward Flow in a Uniform Soil

    Horizontal and Upward Flow in a Uniform Soil

    Flow in a Layered Soil

    HYDRAULIC CONDUCTIVITY

    Temperature Effect

    Particle Size

    Pore Properties

    X-Ray Stereoradiograph Method

    Other Approaches to Permeability

    Hydraulic Gradient Effects

    Average Hydraulic Conductivity

    Unsaturated Hydraulic Conductivity

    SOME SPECIAL PROBLEMS

    Entrapped Air

    Capillary Syphon Flow

    Capillary Fringe and Water Flow

    Unsaturated Downward Flow in Layered Soil

    Infiltration

    General Concepts

    Downward Infiltration into a Uniform Soil

    Downward Infiltration into a Layered Soil

    Horizontal Water Flow

    Upward Flow

    RECENT DEVELOPMENTS IN FINGERING RESEARCH

    Characteristic Features of Fingering

    Criteria for Wetting Front Instability and Finger Width

    Mechanism of Finger Persistence

    References

    UNSATURATED WATER MOVEMENT

    LIMITATIONS ON THE VALIDITY OF DARCY’S LAW

    Darcy’s Law and the Capillary Model

    Experimental Results

    Other Theories of Water Flow

    Unsaturated Flow Theory Including Interfacial Phenomena

    Non-Newtonian and Bingham Flow

    Film Water Flow

    HETEROGENEITY OF HYDRAULIC CONDUCTIVITY IN SOIL

    Introduction

    Scale Effect and Representative Elementary Volume in Soil
    Scale Effect

    Estimation of REV

    Determination of Range of Influence

    The Semi-Variogram

    Estimation of Parameters in the Semi-Variogram Function

    Effect of Sample Size on Range of Influence

    Spatial Dependence of Hydraulic Conductivity in the Field

    Stochastic Theory for Water Flow in Heterogeneous Soil

    SOLUTE MOVEMENT IN FIELD SOILS

    Historical Review

    Limitations on the Validity of the Convection-Dispersion Equation

    Experimental Results

    Theoretical Results

    Investigation of Conditions in the Theoretical Derivation of the Convection-Dispersion Equation

    Physical Meaning of REV in Solute Movement

    Does Asymptotic Behavior Exist?

    REV for Solute Transport

    APPLICATION OF FRACTAL THEORY TO SOLUTE AND WATER FLOWS IN FIELD SOIL

    Concepts of Fractal Geometry

    Estimation of Fractal Dimension

    Fractal Dimension of a Curve

    Fractal Dimension of the Distribution Pattern of an Object Distributed in Space

    Examples

    Use of Fractal Dimension for Predicting Bypass Flow

    Estimation of the Brenner Number Using the Fractal Dimension

    An Explanation of Scale-Dependent Dispersivity Based on Fractal Geometry

    References

    FIELD WATER REGIMES

    WATER IN UPLAND SOILS

    Physical Properties

    Water Regimes in Upland Soils in Japan

    Water Movement in Upland Soils

    WATER BALANCE IN RICE PADDY FIELDS

    Types of Paddy Fields

    Water Requirement in Paddy Fields

    Percolation and Rice Growth

    Soil Properties of Paddy Fields

    Control of Percolation in Paddy Fields

    Puddling

    DRAINAGE OF CLAYEY RICE PADDY FIELDS

    General Pattern of Drainage in a Clayey Paddy Field

    Drainage Conditions in a Clayey Paddy Field

    Effect of Subsurface Drains

    INTERACTION OF CHEMICALS AND WATER IN PADDY FIELDS

    Improvement of Paddy Fields Contaminated by Cadmium

    Nitrogen and Phosphorus Concentrations in a Paddy Field

    Nitrogen and Phosphorous Budgets in Paddy Fields

    Nitrogen Removal in Paddy Fields

    References

    Index

    Biography

    Shingo Iwata

    ". . .breaks out of the common orbit of soil physics monographs. . . . . .Its individuality will add diversity to the libraries both of institutions and of students. "
    ---Irrigation Science