Coastal Storms Processes and Impacts Hydrometeorological Extreme Events Series

A comprehensive introduction to coastal storms and their associated impacts

Coastal Storms offers students and professionals in the field a comprehensive overview and groundbreaking text that is specifically devoted to the analysis of coastal storms. Based on the most recent knowledge and contributions from leading researchers, the text examines coastal storms? processes and characteristics, the main hazards (such as overwash, inundation and flooding, erosion, structures overtopping), and how to monitor and model storms. The authors include information on the most advanced innovations in forecasting, prediction, and early warning, which serves as a foundation for accurate risk evaluation and developing adequate coastal indicators and management options.

In addition, structural overtopping and damage are explained, taking into account the involved hydrodynamic and morphodynamic processes. The monitoring methods of coastal storms are analyzed based on recent results from research projects in Europe and the United States. Methods for vulnerability and risk evaluation are detailed, storm impact indicators are suggested for different hazards and coastal management procedures analyzed. This important resource includes:

• Comprehensive coverage of storms and associated impacts, including meteorological coastal storm definitions and related potential consequences
• A state-of-the-art reference for advanced students, professionals and researchers in the field
• Chapters on monitoring methods of coastal storms, their prediction, early warning systems, and modeling of consequences
• Explorations of methods for vulnerability and risk evaluation and suggestions for storm impact indicators for different hazards and coastal management procedures

Coastal Storms is a compilation of scientific and policy-related knowledge related to climate-related extreme events. The authors are internationally recognized experts and their work reflects the most recent science and policy advances in the field.

List of Contributors xi

Series Foreword xv

Introduction xvii

Acknowledgments xix

1 Coastal Storm Definition 1
Mitchell Harley

1.1 Introduction 1

1.1.1 The challenge of defining coastal storms 4

1.1.2 A general coastal storm definition 7

1.1.3 Approaches to assessing coastal storminess 8

1.2 Synoptic systems and coastal storms 9

1.2.1 Tropical cyclones 9

1.2.2 Extra-tropical cyclones 10

1.2.3 Storm surge 11

1.3 Statistical approaches to identifying coastal storms 12

1.3.1 Coastal storm events from wave time-series 12

1.3.2 Coastal storm events from water-level time-series 15

1.3.3 Indicators of coastal storm severity 16

1.4 Conclusion 18

References 19

2 Hydrodynamics Under Storm Conditions 23
Xavier Bertin, Maitane Olabarrieta and Robert McCall

2.1 General introduction 23

2.2 Storm surges 23

2.2.1 Introduction 23

2.2.2 Governing equations 24

2.3 Hydrodynamics of the surf zone during storms 31

2.3.1 Introduction 31

2.3.2 Longshore currents 31

2.3.3 Bed return flows 32

2.3.4 Infragravity waves 33

2.3.5 Swash zone dynamics 35

2.4 Conclusions and future challenges 38

Acknowledgements 38

References 39

3 Sediment Transport Under Storm Conditions on Sandy Beaches 45
Troels Aagaard and Aart Kroon

3.1 Introduction 45

3.2 Morphological consequences of coastal storms 46

3.3 Sediment transport processes during storms 48

3.4 Observations of sediment transport on the upper shoreface during storm events 53

3.5 Observations of sediment transport on the lower shoreface during storm events 58

3.6 Conclusions 60

Acknowledgements 60

References 60

4 Examples of Storm Impacts on Barrier Islands 65
Nathaniel Plant, Kara Doran and Hilary Stockdon

4.1 Introduction 65

4.2 Barrier island response to storms 66

4.3 Quantifying the changes due to specific storms 70

4.4 Resilience 75

4.5 Summary 76

Acknowledgements 77

References 77

5 Storm Impacts on the Morphology and Sedimentology of Open-coast Tidal Flats 81
Ping Wang and Jun Cheng

5.1 Introduction 81

5.2 Sedimentologic characteristics 83

5.3 Erosion-deposition processes and morphodynamics of open-coast tidal flat 88

5.4 Conclusions 96

References 96

6 Storm Impacts on Cliffed Coastlines 99
Sue Brooks and Tom Spencer

6.1 Introduction 99

6.2 Methodologies and their application 104

6.3 Storminess and the cliff record 106

6.4 Case study: Soft rock cliff geology and responses to storms 110

6.5 Modelling shoreline retreat for cliffed coasts and the incorporation of storminess 115

6.6 Future storm impacts on clifflines under accelerated sea-level rise and changing storminess 117

6.7 Conclusions 119

Acknowledgements 119

References 119

7 Storms in Coral Reefs 127
Ana Vila-Concejo and Paul Kench

7.1 Introduction 127

7.2 Geomorphic units of reefs 129

7.2.1 Reefs as ecomorphodynamic structures 130

7.2.2 Unique interactions of storm waves with coral reefs 132

7.3 Storms on the forereef: Role of spurs and grooves 134

7.3.1 Destructive effects of storms in the forereef and spur and groove 135

7.3.2 Constructive effects of storms in the forereef 136

7.4 Storms on the reef flats: Development of rubble flats and rubble spits 136

7.4.1 Waves on the reef flats 136

7.4.2 Destructive effects of storms on reef flats 136

7.4.3 Constructive effects of storms on reef flats 137

7.5 Storms on the backreef: Sand aprons, reef islands and beaches 139

7.5.1 Sand aprons 139

7.5.2 Reef islands 139

7.6 Conclusion 145

Acknowledgements 145

References 145

8 Storm Clustering and Beach Response 151
Nadia Senechal, Bruno Castelle and Karin R. Bryan

8.1 Introduction 151

8.2 Storm clustering: Genesis and definitions 153

8.2.1 Genesis 153

8.2.2 Definitions 154

8.3 Approaches used to assess storm clustering impact on coasts 156

8.3.1 Data collection 156

8.3.2 Numerical models 157

8.4 Beach response to storm cluster 159

8.4.1 Bar dynamics under storm clustering 159

8.4.2 Morphological feedback 160

8.4.3 The dynamic equilibrium concept 162

8.4.4 Water level 164

8.4.5 Recovery periods 165

8.5 Conclusions 167

References 167

9 Overwash Processes: Lessons from Fieldwork and Laboratory Experiments 175
Ana Matias and Gerhard Masselink

9.1 Introduction 175

9.1.1 Overwash definition 175

9.1.2 Occurrence of overwash 177

9.1.3 Relevance of overwash 180

9.2 Methods to study overwash processes 180

9.2.1 Fieldwork measurements 180

9.2.2 Laboratory experiments 181

9.3 Hydrodynamic processes during overwash 183

9.3.1 Oceanographic conditions 183

9.3.2 Hydraulics of overwash flows 183

9.4 Morpho-sedimentary dynamics by overwash processes 185

9.4.1 Morphological changes induced by overwash 185

9.4.2 Morphodynamic processes during overwash 187

9.5 Conclusion 189

Acknowledgements 190

References 190

10 Modeling the Morphological Impacts of Coastal Storms 195
Ap van Dongeren, Dano Roelvink, Robert McCall, Kees Nederhoff and Arnold van Rooijen

10.1 Introduction 195

10.1.1 Empirical models 196

10.1.2 Process-based models 197

10.1.3 Process-model applications 201

10.1.4 Operational models 209

10.2 Outlook 209

Acknowledgements 210

References 210

11 Preparing for the Impact of Coastal Storms: A Coastal Manager-oriented Approach 217
José Jiménez, Clara Armaroli and Eva Bosom

11.1 Introduction 217

11.2 Coastal vulnerability assessment framework 219

11.2.1 General framework 219

11.2.2 How to characterize storm-induced hazards 219

11.2.3 How to measure the vulnerability 221

11.2.4 How to select the probability to be analyzed 222

11.2.5 The Catalonia coastal vulnerability assessment framework 223

11.3 Coastal early warning systems 227

11.3.1 Generalities 227

11.3.2 Coastal EWSs 228

11.3.3 The Emilia-Romagna coastal early warning system 228

11.4 Conclusion 234

Acknowledgements 235

References 235

12 Assessing Storm Erosion Hazards 241
Roshanka Ranasinghe and David Callaghan

12.1 Introduction 241

12.2 The diagnostic conundrum 242

12.3 Quantifying storm erosion volumes for coastal management/planning 243

12.3.1 Coastal profile model application with Extrapolated Wave Exceedance Characteristics (EWEC) 243

12.3.2 Coastal profile model application with the Synthetic Design Storm (SDS) approach 245

12.3.3 The Joint Probability Method (JPM) approach 246

12.3.4 Corbella and Stretch (CS) approach 248

12.4 Application of storm erosion volume estimates in coastal management/planning 250

12.5 Conclusions and recommendations 251

Acknowledgments 254

References 254

Conclusions and Future Perspectives 257

Index 259

Paolo Ciavola is an Associate Professor of Geomorphology at the University of Ferrara, where he teaches courses of geomorphology and coastal risk. He holds an MSc in Geology from the University of Bologna (Italy) and a PhD in Marine Sciences from the University of Algarve (Portugal). He has an interest in coastal processes and risk from extreme storms.

Giovanni Coco is an Associate Professor in the School of Environment at the University of Auckland, where he teaches courses on modelling environmental systems. He holds a PhD in Marine Studies from the University of Plymouth (UK). His interests range from coastal processes to machine learning and pattern formation.