INTRODUCTION TO COASTAL ENGINEERING AND MANAGEMENT

Advanced Series on Ocean Engineering Volume 16 INTRODUCTION TO COASTAL ENGINEERING AND MANAGEMENT J. William Kamphuis Queen's University, Canada World Scientific Singapore New Jersey London Hong Kong

Contents Preface ix Contents, xi Notation xxi 1. Introduction 1 1.1 Introduction 1 1.2 Synthesis 3 1.3 Simplification 5 1.4 Systems 5 1.5 Jargon and Terminology 9 1.6 Engineering Time 11 1.7 Handy References 11 1.8 Data Requirements 13 1.9 Coastal Design 17 1.10 Concluding Remarks 19 2. Water Waves 21 2.1 Introduction 21 2.1.1 Description of Waves 21 2.1.2 Wind and Waves 23 2.1.3 Sea and Swell 25 2.1.4 Introduction of Small Amplitude Theory Wave 28 2.2 Wave Theories 30 2.3 Small Amplitude Wave Theory 31 2.3.1 Wave Tables 36 2.3.2 Small Amplitude Expressions 36 xi

xii Introduction to Coastal Engineering and Management 2.3.3 Calculation by Computer 41 2.4 Reflected Waves 41 2.5 Wave Measurement 45 2.5.1 Wave Direction 45 2.5.2 Equipment 46 2.5.3 Laboratory Sensors 49 2.6 Summary, 50 3. Short-Term Wave Analysis 51 3.1 Introduction 51 3.2 Short-Term Wave Height Distribution 54 3.3 Wave Period Distribution 59 3.4 Time Domain Analysis of a Wave Record 60 3.5 Frequency Domain Analysis of a Wave Record 64 3.6 Parameters Derived from the Wave Spectrum 69 3.7 Uncertainties in Wave Measurements 73 3.8 Common Parametric Expressions for Wave Spectra 75 3.8 Directional Wave Spectra 79 4. Long-Term Wave Analysis 81 4.1 Introduction 81 4.2 Statistical Analysis of Grouped Wave Data 82 4.3 Transformation of Coordinate Axes 84 4.3.1 Normal Probability Distribution 86 4.3.2 Log-Normal Probability Distribution 87 4.3.3 Gumbel Distribution 89 4.3.4 Weibull Distribution 90 4.4 Extrapolation 93 4.5 Sensitivity to Distribution and Threshold Wave Height 94 4.6 Extreme Value Analysis From Ordered Data 95 4.7 Conclusions About Wave Heights 99 4.8 Other Long-Term Wave Distributions 100 5. Wave Generation 103 5.1 Wave Generation 103 5.2 Simple Wave Hindcasting ' 105 5.2.1 Introduction to Parametric Methods 105 5.2.2 Wind ZZZZZZZZ... 106 5.2.3 Jonswap Parameters 107 5.2.4 Maximum Wave Conditions Ill 5.2.5 Finite Water Depth 113

Contents xiii 5.3 Hindcast Models 113 5.3.1 Parametric Models 114 5.3.2 Wave Spectra Models 116 5.3.3 More Complex Hindcasting Models 116 5.4 Uncertainty 116 6. Tides and Water Levels 117 6.1 Introduction 117 6.2 Tides 118 6.2.1 Equilibrium Tide (Moon) 118 6.2.2 Equilibrium Tide (Sun and Moon) 119 6.2.3 Daily Inequality 121 6.2.4 Other Effects 122 6.2.5 Tide Analysis and Prediction 123 6.2.6 Tidal Currents 124 6.2.7 Stratification and Density Currents 129 6.2.8 Tidal Computation 133 6.3 Storm Surge 134 6.4 Barometric Surge 136 6.5 Seiche 137 6.6 Seasonal Fluctuations 140 6.7 Long-Term Water Level Changes 141 6.7.1 Climatic Fluctuations 141 6.7.2 Eustatic (Sea) Level Change 141 6.7.3 Isostatic (Land) Rebound and Subsidence 142 6.7.4 Global Climate Change 144 7. Wave Transformation and Breaking 149 7.1 Wave Transformation Equations 149 7.2 Wave Shoaling 151 7.3 Wave Refraction 152 7.3.1 The Equations 152 7.3.2 Refraction Diagrams 153 7.3.3 Snell's Law 156 7.3.4 Summary 158 7.4 Wave Breaking 160 7.5 Wave Diffraction 164 7.6 Uncertainty 167

xiv Introduction to Coastal Engineering and Managemen 8. Design of Structures 169 8.1 Introduction 169 8.2 Basics of Risk Analysis 170 8.2.1 Introduction 170 8.2.2 Probability of Failure 171 8.2.3 Levels Of Probabilistic Design 172 8.3 Level II Demonstration 172 8.3.1 Equations 172 8.3.2 Two Probability Distributions 173 8.3.3 One Single Distribution 176 8.3.4 Example Calculations 177 8.4 Extension to More Complex Designs 178 8.5 Encounter Probability 179 8.6 Level I Design 180 8.7 Risk and Damage 181 8.8 The Design Wave 183 8.8.1 Wave Statistics 183 8.8.2 Equivalence of Design Wave Height and Failure Probability 183 8.8.3 Offshore Design Wave Height 184 8.8.4 Design Wave Height for Non-Breaking Waves 185 8.8.5 Design Wave Height for Breaking Waves 187 8.8.6 Model Study 189 8.9 Water Levels 189 9. Breakwaters, 191 9.1 Vertical Breakwaters 191 9.1.1 Introduction 191 9.1.2 Forces for Non-Breaking Waves 193 9.1.3 Forces for Breaking Waves 197 9.1.4 Stability Design 200 9.1.5 Geotechnical Stability 201 9.1.6 Other Design Considerations 203 9.2 Design Examples 204 9.2.1 Vertical Breakwater in 12 m of Water with a Short Fetch 204 9.2.2 Vertical Breakwater in 12 m of Water on an Open Coast 206 9.2.3 Vertical Breakwater in 3 m of Water 208 9.2.4 Summary 209 9.3 Rubble Mound Breakwaters 210 9.3.1 Filter Characteristics 210 9.3.2 Rock Armor 212 9.3.3 Concrete Armor 214

Contents xv 9.3.4 Armor Unit Density 217 9.3.5 Primary Armor Layer 217 9.3.6 Breakwater Crest 218 9.4 Design Examples 220 9.4.1 Breakwater in 12 m of Water 220 9.4.2 Breakwater in 3 m of Water 223 9.4 Berm Breakwaters 224 10. Introduction to Coastal Management 227 10.1 Introduction 227 10.2 The Coast under Pressure 228 10.3 Conforming Use 229 10.4 Conflict and Compatibility 233 10.5 Management Strategies 234 10.6 Coastal Management in Spite of the Odds 237 10.7 Management of Coastal Lands 239 10.8 Management of Coastal Waters 241 10.8.1 Groundwater 241 10.8.2 Waste Water 242 10.8.3 Other Forms of Pollution 243 10.9 Example: Management of the Great Lakes - St Lawrence Shoreline 245 10.10 Example: Management of Coastal Ecosystems 251 10.11 Concluding Remarks 254 11. Coastal Sediment Transport 257 11.1 Introduction 257 11.2 Dynamic Beach Profile 257 11.3 Cross-shore Transport 261 11.3.1 Dune-Beach Utopia 262 11.2.3 Dune-Beach Disturbance 262 11.3.3 Dune-Beach Encouragement 266 11.3.4 Soft Protection 269 11.4 Alongshore Transport 271 11.4.1 The Process 271 11.4.2 Measurement of Littoral Transport 272 11.4.3 Computation of Littoral Transport 273 11.5 Complications 274 11.5.1 Limited Amounts of Beach Material 274 11.5.2 Sediment Transport in Two Directions 275 11.5.3 Short Term Littoral Transport 277 11.6 Cohesive Shores 277

xvi Introduction to Coastal Engineering and Managemen 12. Basic Shore Processes 281 12.1 Introduction 281 12.2 Nearshore Current Patterns 281 12.3 Littoral Materials 283 12.4 The Beach 285 12.4.1 Beach Slope 285 12.4.2 Beach Profile 286 12.5 Cross Shore Sediment Transport 288 12.6 Alongshore Sediment Transport Rate 290 12.6.1 Alongshore Component of Wave Power 291 12.6.2 CERC Expression 292 12.6.3 Kamphuis (1991) Expression 292 12.7 Actual Alongshore Sediment Transport Rate 294 12.8 The Littoral Cell 295 12.9 Uncertainty 297 13. Coastal Design 299 13.1 Introduction 299 13.2 Model Classification 301 13.2.1 Time-Space Classification 301 13.2.2 Classification by Purpose 303 13.3 Physical Models 304 13.3.1 General 304 13.3.2 Scaling and Scale Effect 305 13.3.3 Laboratory Effect 310 13.3.4 Implications for Physical Modeling 310 13.4 Numerical Modeling 311 13.4.1 General 311 13.4.2 Simplifications of Three Dimensional Models 313 13.4.3 One Dimensional Models and their Extensions 315 13.4.4 Performance of Coastal Models 316 13.5 Field Measurement and Data Models 318 13.6 Uncertainty 319 13.7 Reducing Uncertainty 320 13.8 Model Interpretation 322 13.9 The Future 324 13.10 Composite Modeling 325 13.11 Summary 329

Contents xvii 14. One-Dimensional Modeling of Coastal Morphology 331 14.1 Introduction 331 14.2 The 1-D Morphology Equation 331 14.3 Sediment Transport Rate 333 14.3.1 Potential Sediment Transport Rate 333 14.3.2 Actual Sediment Transport Rate 334 14.4 Wave Transformation Computation 334 14.4.1 Wave Shoaling, Refraction and Breaking 334 14.4.2 Wave Diffraction 335 14.5 Analytical Computation of Shore Morphology 337 14.5.1 Simplifications and Assumptions 337 14.5.2 Complete Barrier Solution 339 14.5.3 Bypassing Barrier Solution 341 14.6 Numerical Solutions 345 14.6.1 Basics 345 14.6.2 Implicit Finite Difference Scheme 347 14.6.3 Boundary Conditions 349 14.6.4 Beach Slope 351 14.6.5 Large Shoreline Curvatures 352 14.6.6 Summary 352 14.7 Examples of ONELINE 353 14.8 Examples of NLINE 359 15. Shore Protection 363 15.1 Introduction 363 15.2 Sediment Movement 365 15.3 Groins 366 15.4 Seawalls 370 15.5 Headlands 372 15.6 Offshore Breakwaters 373 15.7 Artificial Nourishment 375 15.8 Water Levels 380 16. Problems 381 16.1 Introduction 381 Problem 1.1 Preparation 381 Problem 1.2 Proposal 382 16.2 Water Waves 383 Problem 2.1 Basic Wave Calculations 383 Problem 2.2 Wave Reflection 383 16.3 Short-Term wave Analysis 384

xvjjj Introduction to Coastal Engineering and Management Problem 3.1 Analysis of Fig 3.4 384 Problem 3.2 Analysis of Collected Wave Data 385 Problem 3.3 Rayleigh Distribution 386 Problem 3.4 Zero Crossing Analysis 386 Problem 3.5 Wave Spectrum 387 Problem 3.6 Laboratory Record 388 16.4 Long-Term Wave Analysis 388 Problem 4.1 Station 13 Data 388 Problem 4.2 North Sea Wave Climate 390 Problem 4.3 Gulf of St. Lawrence Climate 390 Problem 4.4 50-year Storm 390 16.5 Wave Hindcasting 390 Problem 5.1 Very Simple Wave Hindcast 390 Problem 5.2 Simple Wave Hindcast 391 Problem 5.3 WAVGEN and Shallow Water 391 16.6 Storm Surge 392 Problem 6.1 Storm Surge at Reeds Bay 392 Problem 6.2 Storm Surge and Waves 392 Problem 6.3 Storm Surge and Waves at Site S 393 16.7 Wave Transformation 393 Problem 7.1 Wave Refraction and Breaking 393 Problem 7.2 Wave Transformation 394 Problem 7.3 Wave Diffraction 394 16.8 Design 395 Problem 8.1 Probability of Failure 395 Problem 8.2 Vertical Breakwwater 396 Problem 8.3 Vertical Breakwater at Site M 397 Problem 8.4 Vertical loading dock on Gulf of St. Lawrence 397 Problem 8.5 Rubble Mound Breakwater 398 Problem 8.6 Rubble Mound Breakwater at Site M 398 16.9 Coastal Management 399 Problem 9.1 Expansion at Site M 399 Problem 9.2 Facilities at Site B 399 Problem 9.3 Development of Property 400 16.10 Sediment Transport and Morphology 401 Problem 10.1 Potential Sediment Transport Rate 401 Problem 10.2 Potential Sediment Transport Rate 401 Problem 10.3 Accretion 401 Problem 10.4 Sediment Transport in two Directions 4^ Problem 10.5 Sea Level Rise 403 Problem 10.6 Northeaster Storm 403

Contents xix 16.11 Modeling 403 Problem 11.1 Physical Models 403 Problem 11.2 Numerical Models 404 16.12 Comprehensive Problems 404 Problem 12.1 Design Analysis 404 Problem 12.2 Design of Breakwater with Parapet Wall 408 Problem 12.3 Vertical Breakwater Design 409 References 411 Author Index 425 Subject Index 429