Note: Intro -- Foreword -- Preface -- Contents -- 1 Background -- 1.1 Physical Properties of Unsaturated Infiltration -- 1.1.1 Basic Physical Properties -- 1.1.2 Soil Suction -- 1.1.3 Unsaturated Hydraulic Conductivity -- 1.1.4 Total Head -- 1.1.5 Soil-Water Characteristic Curve -- 1.2 Governing Equation of Water Infiltration -- 1.2.1 Richards' Equation -- 1.3 Shear Strength and Slope Stability -- 1.3.1 Unsaturated Shear Strength -- 1.3.2 Slope Stability -- References -- 2 Analytical Solution to 1D Coupled Infiltration and Deformation in Unsaturated Porous Media -- 2.1 Introduction -- 2.2 Effect of Rainfall Pattern -- 2.2.1 Governing Equations for Coupled Seepage and Deformation -- 2.2.1.1 Coupled Governing Equations -- 2.2.1.2 Constitutive Relationships for Soil Solids -- 2.2.2 Analytical Solutions to 1D Coupled Infiltration Problems Before and After Ponding -- 2.2.2.1 Coupled Conditions -- 2.2.2.2 Uncoupled Conditions -- 2.2.3 Examples and Analysis Results -- 2.2.4 Conclusions -- 2.3 Effect of Boundary Condition -- 2.3.1 Coupled Infiltration Equations -- 2.3.2 Solution for Infiltration into Deformable Soils -- 2.3.3 Example -- 2.3.3.1 Influence of Rainfall Intensity -- 2.3.3.2 Effect of the Desaturation Coefficient -- 2.3.3.3 Effect of F -- 2.3.3.4 Effect of the Soil Layer Height -- 2.3.4 Conclusions -- 2.4 Effect of Layered Structure -- 2.4.1 Governing Equations -- 2.4.2 Parametric Study -- 2.4.2.1 Effect of H -- 2.4.2.2 Effect of ks -- 2.4.2.3 Effect of α -- 2.4.2.4 Effect of Soil Porosity θsb and θst -- 2.4.2.5 Effect of qA and qB -- 2.4.2.6 Effect of Air-Entry Value -- 2.4.3 Conclusions -- Appendix -- References -- 3 Effects of Gravity and Hysteresis on 1D Unsaturated Infiltration -- 3.1 Introduction -- 3.2 Effect of Gravity -- 3.2.1 Governing Equation -- 3.2.1.1 1D Vertical Infiltration -- 3.2.1.2 1D Horizontal Infiltration. , 3.2.2 Boundary and Initial Conditions -- 3.2.2.1 Bottom Boundary -- 3.2.2.2 Prescribed Flux for Surface Condition or Right Boundary -- 3.2.2.3 Constant Pressure Head for Surface and Right Boundaries -- 3.2.2.4 Initial Conditions -- 3.2.3 The Analytical Solutions for Transient Unsaturated Infiltration -- 3.2.3.1 The Analytical Solution to 1D Horizontal Infiltration -- 3.2.3.2 The Analytical Solution to 1D Vertical Infiltration -- 3.2.4 The Analytical Solution for Steady Unsaturated Infiltration -- 3.2.4.1 Vertical Infiltration -- 3.2.4.2 Horizontal Infiltration -- 3.2.5 Case Study and Analysis -- 3.2.6 Summary -- 3.3 Effect of Hysteresis -- 3.3.1 Brief Review of Hysteretic Soil-Water Characteristic Models -- 3.3.2 Mathematical Formulations for Hysteresis -- 3.3.3 Analytical Solutions Considering Hysteresis -- 3.3.3.1 1D Analytical Solution -- 3.3.3.2 Hysteresis Analysis -- 3.3.4 Analysis Examples -- 3.3.5 Conclusions -- 3.4 Effect of Semi-infinite Region -- 3.4.1 Governing Equation -- 3.4.1.1 Coupled Governing Equations -- 3.4.1.2 Analytical Solutions to 1D Semi-infinite Coupled Transient Infiltration -- 3.4.2 Parametric Study -- 3.4.2.1 Effect of the Dimensionless Rainfall Intensity: q/ks -- 3.4.2.2 Effect of the Desaturation Coefficient: α -- 3.4.2.3 Effect of the Initial Pore-Water Pressure: ur -- 3.4.3 Conclusions -- References -- 4 2D Infiltration in Unsaturated Porous Media -- 4.1 Introduction -- 4.2 Analytical Solution to Finite Domain -- 4.2.1 Governing Equation of Coupled Infiltration Problems -- 4.2.2 Formulation of the Initial Value Problem -- 4.2.3 Analytical Solutions to Two-Dimensional Coupled Infiltration -- 4.2.4 Numerical Results -- 4.2.5 Conclusions -- 4.3 Numerical Solution to Water Table Rise -- 4.3.1 Governing Equations for the Hydromechanical Processes Involved in Water Table Change -- 4.3.1.1 Static Equilibrium Equations. , 4.3.1.2 van Genuchten Model -- 4.3.1.3 Seepage Equations -- 4.3.2 Computational Modeling -- 4.3.3 Examples of Water Infiltration -- 4.3.3.1 Example 1 -- 4.3.3.2 Example 2 -- 4.3.4 Discussion and Conclusions -- 4.3.4.1 Discussion -- 4.3.4.2 Conclusions -- 4.4 Surface Infiltration in Semi-infinite Extent -- 4.4.1 Governing Equations for Coupled Seepage and Deformation in Unsaturated Soils -- 4.4.2 Analytical Solution to the Coupled Infiltration in a Semi-infinite Region -- 4.4.3 Computational Modeling of Water Infiltration in a Semi-infinite Unsaturated Region -- 4.5 Conclusions -- References -- 5 Physical Simulation of Rainfall Infiltration into Unsaturated Slopes -- 5.1 Introduction -- 5.2 Physical Testing of Rainfall-Induced Loose Deposit Slope Failures -- 5.2.1 Model Design -- 5.2.1.1 Experiment Design -- 5.2.2 Analysis of the Slope Model Experiments -- 5.2.3 Conclusions -- 5.3 Laboratory Simulation of Rainfall-Induced Loess Slope Failure -- 5.3.1 Methods -- 5.3.1.1 Experiment Design -- 5.3.1.2 Experimental Process -- 5.3.2 Results and Analysis -- 5.3.2.1 Slope Hydrology -- 5.3.2.2 Slope Deformation -- 5.3.2.3 Analysis of the Landslide Process -- 5.3.3 Numerical Analysis -- 5.3.4 Conclusions -- 5.4 Model Test for Rainfall-Induced Shallow Landslides in Red-Bed Area -- 5.4.1 Geographic and Geologic Setting -- 5.4.2 Theoretical Modeling of Rainfall-Induced Shallow Landslides -- 5.4.2.1 Modified Green-Ampt Rainfall Infiltration Model -- 5.4.2.2 Theoretical Model for Shallow Landslides -- 5.4.3 Laboratory Model Testing of Rainfall-Induced Landslides -- 5.4.3.1 Model Tests -- 5.4.3.2 Volumetric Water Content, Matric Suction, and Pore-Water Pressure Monitoring -- 5.4.3.3 Deformation and Failure Characteristics of the Landslide -- 5.4.4 Verification of the Infiltration Analysis Model -- 5.4.5 Comparative Analysis of the Shallow Landslide Model. , 5.4.6 Conclusions -- References -- 6 Slope Stability Analysis Based on Coupled Approach -- 6.1 Introduction -- 6.2 Hydromechanical Process of Soil Slope Under Rainfall -- 6.2.1 Equations Governing Coupled Infiltration and Deformation -- 6.2.2 The Limit Equilibrium Method for Stability of an Infinite Soil Slope -- 6.2.3 Analytical Solutions to Rainfall Infiltration in an Infinite Slope -- 6.2.4 Examples and Results -- 6.2.4.1 Influence of Rainfall Intensity on the Pressure Head Section and Stability of the Slope -- 6.2.4.2 Effect of the Slope Height on the Pressure Head Profile and the Stability of the Slope -- 6.2.4.3 Effect of the Slope Angle on the Pressure Head Profile and the Stability of the Slope -- 6.2.5 Conclusions -- 6.3 Hydromechanical Coupling of Unsaturated Soil Slope Stability Due to Rainfall Patterns -- 6.3.1 Theory -- 6.3.1.1 The Soil-Water Characteristic Curves -- 6.3.1.2 Governing Equation of Coupled Infiltration and Deformation -- 6.3.1.3 Solving the Coupled Governing Equations -- 6.3.2 Numerical Calculation of a Homogeneous Soil Slope -- 6.3.2.1 Model and Parameters -- 6.3.2.2 Influence of the Rainfall Pattern -- 6.3.2.3 Effects of the Coefficient of Permeability -- 6.3.3 Conclusions -- 6.4 Three-Phase Coupling of Soil Slope Under Rainfall -- 6.4.1 The Coupled Model -- 6.4.1.1 van Genuchten Model -- 6.4.1.2 Mass Conservation Equations -- 6.4.2 Equilibrium Equation -- 6.4.3 Analysis of Unsaturated Soil Slope Stability -- 6.4.4 Case Studies -- 6.4.4.1 Boundary and Initial Conditions -- 6.4.4.2 Analysis Considering Soil Anisotropy -- 6.4.4.3 Results Considering Anisotropic Properties -- 6.4.5 Conclusions -- Appendix -- References.