Applied Groundwater Modeling: Simulation of Flow and Advective Transport

This second edition is extensively revised throughout with expanded discussion of modeling fundamentals and coverage of advances in model calibration and uncertainty analysis that are revolutionizing the science of groundwater modeling. The text is intended for undergraduate and graduate level courses in applied groundwater modeling and as a comprehensive reference for environmental consultants and scientists/engineers in industry and governmental agencies. Explains how to formulate a conceptual model of a groundwater system and translate it into a numerical model Demonstrates how modeling concepts, including boundary conditions, are implemented in two groundwater flow codes-- MODFLOW (for finite differences) and FEFLOW (for finite elements) Discusses particle tracking methods and codes for flowpath analysis and advective transport of contaminants Summarizes parameter estimation and uncertainty analysis approaches using the code PEST to illustrate how concepts are implemented Discusses modeling ethics and preparation of the modeling report Includes Boxes that amplify and supplement topics covered in the text Each chapter presents lists of common modeling errors and problem sets that illustrate concepts INDICE: List of Figures List of Tables Preface Disclaimer Acknowledgments Section 1 Modeling Fundamentals 1. Introduction 1.1 Motivation for Modeling 1.2 What Is a Model? 1.2.1 Physical Models 1.2.2 Mathematical Models 1.3 Purpose of Modeling 1.3.1 Forecasting/Hindcasting Models 1.3.2 Interpretative Models 1.4 Limitations of Models 1.4.1 Nonuniqueness 1.4.2 Uncertainty 1.5 Modeling Ethics 1.5.1 Model Design 1.5.2 Bias 1.5.3 Presentation of Results 1.5.4 Cost 1.6 Modeling Workflow 1.6.1 Steps in the Workflow 1.6.2 Verification and Validation 1.7 Common Modeling Errors 1.8 Use of This Text 1.9 Problems References Box 1.1 Data-Driven (Black-Box) Models 2. Modeling Purpose and Conceptual Model 2.1 Modeling Purpose 2.2 Conceptual Model: Definition and General Features 2.3 Components of a Conceptual Model 2.3.1 Boundaries 2.3.2 Hydrostratigraphy and Hydrogeological Properties 2.3.3 Flow Direction and Sources and Sinks 2.3.4 Groundwater Budget Components 2.3.5 Ancillary Information 2.4 Uncertainty in the Conceptual Model 2.5 Common Modeling Errors 2.6 Problems References Box 2.1 Geographical Information Systems (GIS) Box 2.2 Describing the Void Space 3. Basic Mathematics and the Computer Code 3.1 Introduction 3.2 Governing Equation for Groundwater Flow 3.2.1 Assumptions 3.2.2 Derivation 3.3 Boundary Conditions 3.4 Analytical Models 3.4.1 Analytical Solutions 3.4.2 Analytic Element (AE) Models 3.5 Numerical Models 3.5.1 Finite Differences 3.5.2 Finite Elements 3.5.3 Control Volume Finite Differences 3.5.4 Solution Methods 3.6 Code Selection 3.6.1 Code Verification 3.6.2 Water Budget 3.6.3 Track Record 3.6.4 GUIs 3.7 Code Execution 3.7.1 Simulation Log 3.7.2 Execution Time 3.7.3 Closure Criteria and Solution Convergence 3.8 Common Modeling Errors 3.9 Problems References Box 3.1 The Hydraulic Conductivity Tensor Box 3.2 Insights from Analytical Solutions Section 2 Designing the Numerical Model 4. Model Dimensionality and Setting Boundaries 4.1 Spatial Dimensions 4.1.1 Two-Dimensional Models 4.1.2 Three-Dimensional Models 4.2 Selecting Boundaries 4.2.1 Physical Boundaries 4.2.2 Hydraulic Boundaries 4.3 Implementing Boundaries in a Numerical Model 4.3.1 Setting Boundaries in the Grid/Mesh 4.3.2 Specified Head Boundaries 4.3.3 Specified Flow Boundaries 4.3.4 Head-dependent Boundaries 4.4 Extracting Local Boundary Conditions from a Regional Model 4.5 Simulating the Water Table 4.5.1 Fixed Nodes 4.5.2 Movable Nodes 4.5.3 Variably Saturated Codes 4.6 Common Modeling Errors 4.7 Problems References Box 4.1 Two-Dimensional or Three-Dimensional-- More about the D-F Approximation Box 4.2 Profile Models Box 4.3 Spreadsheet Solution of a Finite-Difference Profile Model Box 4.4 The Freshwater--Seawater Interface Box 4.5 Large Water Budget Errors Arising from an HDB Box 4.6 What Controls the Water Table? 5. Spatial Discretization and Parameter Assignment 5.1 Discretizing Space 5.1.1 Orienting the Grid/Mesh 5.1.2 Finite-Difference Grid 5.1.3 Finite-Element Mesh 5.2 Horizontal Nodal Spacing 5.2.1 Solution Accuracy 5.2.2 Calibration Targets 5.2.3 Perimeter Boundary Configuration 5.2.4 Heterogeneity 5.2.5 Faults, Conduits, and Barriers 5.2.6 Internal Sources and Sinks 5.3 Model Layers 5.3.1 Vertical Discretization 5.3.2 Layer Types 5.3.3 Layer Elevations 5.3.4 Pinchouts and Faults 5.3.5 Dipping Hydrogeologic Units 5.4 Parameters 5.4.1 Material Property Parameters 5.4.2 Hydrologic Parameters 5.5 Parameter Assignment 5.5.1 General Principles 5.5.2 Assigning Storage Parameters to Layers 5.5.3 Populating the Grid or Mesh 5.6 Parameter Uncertainty 5.7 Common Modeling Errors 5.8 Problems References Box 5.1 Numerical Error Inherent to Irregular FD Grids Box 5.2 Vertical Anisotropy and the Transformed Section Box 5.3 Upscaling Hydraulic Conductivity: Layered Heterogeneity and Vertical Anisotropy Box 5.4 When Infiltration becomes Recharge 6. More on Sources and Sinks 6.1 Introduction 6.2 Pumping and Injection Wells 6.2.1 FD Well Nodes 6.2.2 FE Well Nodes and Multinode Wells 6.2.3 Multinode Wells in FD Models 6.3 Areally Distributed Sources and Sinks 6.4 Drains and Springs 6.5 Streams 6.6 Lakes 6.7 Wetlands 6.8 Common Modeling Errors 6.9 Problems References Box 6.1 Guidelines for Nodal Spacing around a Well Node Box 6.2 Watershed Modeling Box 6.3 Surface Water Modeling 7. Steady-State and Transient Simulations 7.1 Steady-State Simulations 7.1.1 Starting Heads 7.1.2 Boundary Conditions 7.1.3 Evaluating Steady-State Conditions 7.2 Steady State or Transient? 7.3 Transient Simulations 7.4 Initial Conditions 7.5 Perimeter Boundary Conditions for Transient Simulations 7.6 Discretizing Time 7.6.1 Time Steps and Stress Periods 7.6.2 Selecting the Time Step 7.7 Characterizing Transient Conditions 7.8 Common Modeling Errors 7.9 Problems References Section 3 Particle Tracking, Calibration, Forecasting and Uncertainty Analysis 8. Particle Tracking 8.1 Introduction 8.2 Velocity Interpolation 8.2.1 Effect of Spatial Discretization 8.2.2 Effect of Temporal Discretization 8.2.3 Interpolation Methods 8.3 Tracking Schemes 8.3.1 Semianalytical Method 8.3.2 Numerical Methods 8.4 Weak Sinks 8.5 Applications 8.5.1 Flow System Analysis 8.5.2 Capture Zones and Contributing Areas 8.5.3 Advective Transport of Contaminants 8.6 Particle Tracking Codes 8.7 Common Errors in Particle Tracking 8.8 Problems References Box 8.1 Effective Porosity Box 8.2 Flow Nets Box 8.3 More on Capture Zones and Contributing Areas 9. Model Calibration: Assessing Performance 9.1 Introduction 9.2 Limitations of History Matching 9.3 Calibration Targets 9.3.1 Head Targets 9.3.2 Flux Targets 9.3.3 Ranking Targets 9.4 Manual History Matching 9.4.1 Comparing Model Output to Observations 9.4.2 Choosing the Parameters to Adjust 9.4.3 Manual Trial-and-Error History Matching 9.4.4 Limitations of a Manual Approach 9.5 Parameter Estimation: Automated Trial-and-Error History Matching 9.5.1 Weighting the Targets 9.5.2 Finding a Best Fit 9.5.3 Statistical Analysis 9.6 Highly Parameterized Model Calibration with Regularized Inversion 9.6.1 Increasing the Number of Calibration Parameters 9.6.2 Stabilizing Parameter Estimation 9.6.3 Speeding the Parameter Estimation Process 9.7 A Workflow for Calibration and Model Performance Evaluation 9.8 Common Modeling Errors 9.9 Problems References Box 9.1 Historical Context for Parameter Estimation Box 9.2 Tips for Running a Parameter Estimation Code Box 9.3 Tips for Effective Pilot Point Parameterization Box 9.4 A Singularly Valuable Decomposition- Benefits for Groundwater Modeling Box 9.5 Code/Model Verification and Model Validation Box 9.6 Additional Parameter Estimation Tools 10. Forecasting and Uncertainty Analysis 10.1 Introduction 10.2 Characterizing Uncertainty 10.3 Addressing Uncertainty 10.4 Basic Uncertainty Analysis 10.4.1 Scenario Modeling 10.4.2 Linear Uncertainty Analysis 10.5 Advanced Uncertainty Analysis 10.5.1 Analysis Using One Conceptualization 10.5.2 Analysis Using Multiple Conceptualizations 10.6 Reporting Forecast Uncertainty 10.7 Evaluating Forecasts: Postaudits 10.8 Common Modeling Errors 10.9 Problems References Box 10.1 Historical Overview of Uncertainty Analysis in Groundwater Modeling Box 10.2 Travel Time in Heterogeneous Aquifers: Impossible to Forecast Accurately? Box 10.3 Cost-Benefit Analyses of Future Data Collection Box 10.4 Using Monte Carlo Methods to Represent Forecast Uncertainty Section 4 The Modeling Report and Advanced Topics 11. The Modeling Report, Archive, and Review 11.1 Introduction 11.2 The Modeling Report 11.2.1 Title 11.2.2 Executive Summary and Abstract 11.2.3 Introduction 11.2.4 Hydrogeologic Setting and Conceptual Model 11.2.5 Numerical Model 11.2.6 Forecasting Simulations and Uncertainty Analysis 11.2.7 Discussion 11.2.8 Model Assumptions, Simplifications, and Limitations 11.2.9 Summary and Conclusions 11.2.10 References Cited 11.2.11 Appendices 11.3 Archiving the Model 11.4 Reviewing the Modeling Report 11.5 Common Errors in Report/Archive Preparation and Review 11.6 Problems References 12. Beyond Basic Modeling Concepts 12.1 Introduction 12.2 Complex Groundwater Flow Processes 12.2.1 Flow through Fractures and Conduits 12.2.2 Aquifer Compaction 12.2.3 Variably Saturated Flow 12.2.4 Variable Density Flow 12.2.5 Multiphase Flow 12.2.6 Linked and Coupled Models 12.3 Transport Processes 12.4 Surface Water Processes 12.5 Stochastic Groundwater Modeling 12.6 Decision-Support and Optimization 12.7 Final Comments References Index

• ISBN: 978-0-08-091638-5
• Editorial: Academic Press
• Encuadernacion: Cartoné
• Páginas: 630
• Fecha Publicación: 25/09/2015
• Nº Volúmenes: 1
• Idioma: Inglés