Preface to the Second Edition xiii

Preface to the First Edition xv

List of Contributors xvii

Part I Model Building 1

1 Introduction 3
John Wainwright and Mark Mulligan

1.1 Introduction 3

1.2 Why model the environment? 3

1.3 Why simplicity and complexity? 3

1.4 How to use this book 5

1.5 The book’s web site 6

References 6

2 Modelling and Model Building 7
Mark Mulligan and John Wainwright

2.1 The role of modelling in environmental research 7

2.2 Approaches to model building: chickens, eggs, models and parameters? 12

2.3 Testing models 16

2.4 Sensitivity analysis and its role 18

2.5 Errors and uncertainty 20

2.6 Conclusions 23

References 24

3 Time Series: Analysis and Modelling 27
Bruce D. Malamud and Donald L. Turcotte

3.1 Introduction 27

3.2 Examples of environmental time series 28

3.3 Frequency-size distribution of values in a time series 30

3.4 White noises and Brownian motions 32

3.5 Persistence 34

3.6 Other time-series models 41

3.7 Discussion and summary 41

References 42

4 Non-Linear Dynamics Self-Organization and Cellular Automata Models 45
David Favis-Mortlock

4.1 Introduction 45

4.2 Self-organization in complex systems 47

4.3 Cellular automaton models 53

4.4 Case study: modelling rill initiation and growth 56

4.5 Summary and conclusions 61

4.6 Acknowledgements 63

References 63

5 Spatial Modelling and Scaling Issues 69
Xiaoyang Zhang Nick A. Drake and John Wainwright

5.1 Introduction 69

5.2 Scale and scaling 70

5.3 Causes of scaling problems 71

5.4 Scaling issues of input parameters and possible solutions 72

5.5 Methodology for scaling physically based models 76

5.6 Scaling land-surface parameters for a soil-erosion model: a case study 82

5.7 Conclusion 84

References 87

6 Environmental Applications of Computational Fluid Dynamics 91
N.G. Wright and D.M. Hargreaves

6.1 Introduction 91

6.2 CFD fundamentals 92

6.3 Applications of CFD in environmental modelling 97

6.4 Conclusions 104

References 106

7 Data-Based Mechanistic Modelling and the Emulation of Large Environmental System Models 111
Peter C. Young and David Leedal

7.1 Introduction 111

7.2 Philosophies of science and modelling 113

7.3 Statistical identification, estimation and validation 113

7.4 Data-based mechanistic (DBM) modelling 115

7.5 The statistical tools of DBM modelling 117

7.6 Practical example 117

7.7 The reduced-order modelling of large computer-simulation models 122

7.8 The dynamic emulation of large computer-simulation models 123

7.9 Conclusions 128

References 129

8 Stochastic versus Deterministic Approaches 133
Philippe Renard, Andres Alcolea and David Ginsbourger

8.1 Introduction 133

8.2 A philosophical perspective 135

8.3 Tools and methods 137

8.4 A practical illustration in Oman 143

8.5 Discussion 146

References 148

Part II The State of The Art in Environmental Modelling 151

9 Climate and Climate-System Modelling 153
L.D. Danny Harvey

9.1 The complexity 153

9.2 Finding the simplicity 154

9.3 The research frontier 159

9.4 Online material 160

References 163

10 Soil and Hillslope (Eco)Hydrology 165
Andrew J. Baird

10.1 Hillslope e-c-o-hydrology? 165

10.2 Tyger tyger. . . 169

10.3 Nobody loves me everybody hates me. . . 172

10.4 Memories 176

10.5 I’ll avoid you as long as I can? 178

10.6 Acknowledgements 179

References 180

11 Modelling Catchment and Fluvial Processes and their Interactions 183
Mark Mulligan and John Wainwright

11.1 Introduction: connectivity in hydrology 183

11.2 The complexity 184

11.3 The simplicity 196

11.4 Concluding remarks 201

References 201

12 Modelling Plant Ecology 207
Rosie A. Fisher

12.1 The complexity 207

12.2 Finding the simplicity 209

12.3 The research frontier 212

12.4 Case study 213

12.5 Conclusions 217

12.6 Acknowledgements 217

References 218

13 Spatial Population Models for Animals 221
George L.W. Perry and Nick R. Bond

13.1 The complexity: introduction 221

13.2 Finding the simplicity: thoughts on modelling spatial ecological systems 222

13.3 The research frontier: marrying theory and practice 227

13.4 Case study: dispersal dynamics in stream ecosystems 228

13.5 Conclusions 230

13.6 Acknowledgements 232

References 232

14 Vegetation and Disturbance 235
Stefano Mazzoleni, Francisco Rego, Francesco Giannino Christian Ernest Vincenot, Gian Boris Pezzatti and Colin Legg

14.1 The system complexity: effects of disturbance on vegetation dynamics 235

14.2 The model simplification: simulation of plant growth under grazing and after fire 237

14.3 New developments in ecological modelling 240

14.4 Interactions of fire and grazing on plant competition: field experiment and modelling applications 242

14.5 Conclusions 247

14.6 Acknowledgements 248

References 248

15 Erosion and Sediment Transport: Finding Simplicity in a Complicated Erosion Model 253
Richard E. Brazier

15.1 The complexity 253

15.2 Finding the simplicity 253

15.3 WEPP ? The Water Erosion Prediction Project 254

15.4 MIRSED ? a Minimum Information Requirement version of WEPP 256

15.5 Data requirements 258

15.6 Observed data describing erosion rates 259

15.7 Mapping predicted erosion rates 259

15.8 Comparison with published data 262

15.9 Conclusions 264

References 264

16 Landslides Rockfalls and Sandpiles 267
Stefan Hergarten

References 275

17 Finding Simplicity in Complexity in Biogeochemical Modelling 277
Hordur V. Haraldsson and Harald Sverdrup

17.1 Introduction to models 277

17.2 The basic classification of models 278

17.3 A ‘good’ and a ‘bad’ model 278

17.4 Dare to simplify 279

17.5 Sorting 280

17.6 The basic path 282

17.7 The process 283

17.8 Biogeochemical models 283

17.9 Conclusion 288

References 288

18 Representing Human Decision-Making in Environmental Modelling 291
James D.A. Millington, John Wainwright and Mark Mulligan

18.1 Introduction 291

18.2 Scenario approaches 294

18.3 Economic modelling 297

18.4 Agent-based modelling 300

18.5 Discussion 304

References 305

19 Modelling Landscape Evolution 309
Peter van der Beek

19.1 Introduction 309

19.2 Model setup and philosophy 310

19.3 Geomorphic processes and model algorithms 313

19.4 Model testing and calibration 318

19.5 Coupling of models 321

19.6 Model application: some examples 321

19.7 Conclusions and outlook 324

References 327

Part III Models for Management 333

20 Models Supporting Decision-Making and Policy Evaluation 335
Mark Mulligan

20.1 The complexity: making decisions and implementing policy in the real world 335

20.2 The simplicity: state-of-the-art policy-support systems 341

20.3 Addressing the remaining barriers 345

20.4 Conclusions 347

20.5 Acknowledgements 347

References 347

21 Models in Policy Formulation and Assessment: The WadBOS Decision-Support System 349
Guy Engelen

21.1 Introduction 349

21.2 Functions of WadBOS 350

21.3 Decision-support systems 351

21.4 Building the integrated model 351

21.5 The integrated WadBOS model 354

21.6 The toolbase 359

21.7 The database 359

21.8 The user-interface 360

21.9 Discussion and conclusions 362

21.10 Acknowledgments 363

References 363

22 Soil Erosion and Conservation 365
Mark A. Nearing

22.1 The problem 365

22.2 The approaches 367

22.3 The contributions of modelling 369

22.4 Lessons and implications 375

22.5 Acknowledgements 376

References 376

23 Forest-Management Modelling 379
Mark J. Twery and Aaron R. Weiskittel

23.1 The issue 379

23.2 The approaches 379

23.3 Components of empirical models 383

23.4 Implementation and use 386

23.5 Example model 390

23.6 Lessons and implications 390

References 391

24 Stability and Instability in the Management of Mediterranean Desertification 399
John B. Thornes

24.1 Introduction 399

24.2 Basic propositions 400

24.3 Complex interactions 403

24.4 Climate gradient and climate change 408

24.5 Implications 409

24.6 Plants 410

24.7 Lessons and implications 411

References 411

25 Operational European Flood Forecasting 415
Hannah Cloke, Florian Pappenberger, Jutta Thielen and Vera Thiemig

25.1 The problem: providing early flood warning at the European scale 415

25.2 Flood forecasting at the European scale: the approaches 416

25.3 The European Flood Alert System (EFAS) 422

25.4 Lessons and implications 429

References 430

26 Assessing Model Adequacy 435
Michael Goldstein Allan Seheult and Ian Vernon

26.1 Introduction 435

26.2 General issues in assessing model adequacy 435

26.3 Assessing model adequacy for a fast rainfall-runoff model 438

26.4 Slow computer models 446

26.5 Acknowledgements 449

References 449

Part IV Current and Future Developments 451

27 Pointers for the Future 453
John Wainwright and Mark Mulligan

27.1 What have we learned? 453

27.2 Research directions 459

27.3 Technological directions 459

27.4 Is it possible to find simplicity in complexity? 463

References 463

Index 465