Coastal and Estuarine Processes

The following sections are included:

• Preface

• Contents

The following sections are included:

• INTRODUCTION
  • The nature of water waves
  • Wave restoring forces
  • Wave generating forces

• DEFINITIONS AND COORDINATE SYSTEMS
  • Waves that propagate with constant form
  • Exercise

• SMALL AMPLITUDE SHALLOW WATER WAVES
  • The ID shallow water wave equation
    • Shallow water sine waves
  • Long waves in two horizontal dimensions
    • Coastal trapped waves
  • Forced shallow water waves
    • Equations of motion
    • Steady forced solutions
    • Influence of bed friction on steady forced waves
    • Long waves growing after abrupt onset of forcing
    • Special behaviour with resonant and near-resonant forcing
    • Analogies in two horizontal dimensions

• SINE WAVES IN ARBITRARY DEPTH
  • The field equations
  • The boundary conditions
  • The form of the solution
  • The dispersion relation
  • The wave length
  • The wave speed
  • The water particle velocities
  • The pressure field
  • The energy density
  • The energy flux
  • Superposition
  • The group velocity
  • Radiation stress or wave thrust
  • Mass transport by sine waves
  • Summary of sine wave formulae
  • Explicit approximations to sine wave formulae

• WAVES OF FINITE HEIGHT
  • Introduction
  • The non-linear shallow water equations
  • Bores
  • Cnoidal waves
  • Stokes waves
  • Fourier expansion methods

• NATURAL, IRREGULAR WAVES
  • Introduction
  • Definition of individual waves and simple statistics
  • The Rayleigh distribution of individual wave heights
  • Long term wave statistics
  • Wave spectra
  • Generation of waves by wind

• WAVES CHANGING DUE TO TOPOGRAPHY
  • Introduction
  • Shoaling of sine waves
  • Refraction
  • Combined refraction and shoaling
  • Sine waves on straight and parallel bottom contours

• DIFFRACTION OF WATER WAVES

• REFLECTION AND SEICHES
  • Superposition of reflected and incoming waves
  • Seiches
  • Reflection from a slope
  • Transmission and reflection at a depth change

• WAVES ENCOUNTERING CURRENTS
  • Introduction
  • Dispersion relation for waves on a current
  • Wave height variation due to varying current speed

• TSUNAMI
  • Introduction
  • Generation of tsunami by tectonic uplift
  • Tsunami generation by gradual sea bed deformations
  • Tsunami generated by a hump sliding on a horizontal sea floor
  • Shoaling, breaking and runup
  • Inundation from tsunami

The following sections are included:

• INTRODUCTION

• SURF ZONE WAVES
  • Breaking or reflection?
  • Breaker types
  • Breaker heights
  • Wave height to water depth ratio after breaking

• THE SHAPE OF THE MEAN WATER SURFACE
  • Terminology and definitions
  • Wave setdown
  • Wave setup
  • Shoreline setup
  • Wave setup in river entrances
  • Surf beat

• SWASH AND RUNUP HEIGHTS
  • Introduction
  • The hydrodynamics
  • Runup heights for regular waves
  • Runup height distribution for irregular waves
  • Extreme runup heights

• WAVE GENERATED LONGSHORE CURRENTS
  • Introduction
  • The driving force
  • The retarding force
  • Estimating the maximum velocity
  • Distribution of the longshore current velocity

• RIP CURRENTS
  • Introduction
  • Occurrence of rip currents
  • Rip spacing
  • Rip flows and wave pump efficiency

• UNDERTOW

The following sections are included:

• INTRODUCTION

• WIND DRIVEN CIRCULATION
  • Introduction
  • Wind stresses on the sea surface
  • Wind driven shorenormal circulation
  • Wind driven steady circulation in a basin
  • Steady wind driven circulation in deep water

• SETUP AND SURGES DUE TO WIND STRESS FIELDS
  • Wind setup from a steady onshore wind
  • Surge due to steady longshore wind
  • Surge due to a moving wind stress field

• BAROMETRIC SETUP AND PRESSURE DRIVEN SURGES
  • The stationary scenario
  • Long waves forced by a moving low pressure system

The following sections are included:

• THE NATURE OF OCEAN TIDES

• THE EQUILIBRIUM THEORY OF TIDES

• MEASURED VERSUS PREDICTED TIDES

• PREDICTING THE ASTRONOMICAL TIDE

• TIDES IN RIVERS
  • The nature of river tides
  • Numerical modelling of river tides

• TIDES IN COASTAL LAGOONS

• NET CIRCULATION DUE TO TIDES IN ESTUARIES

• TIDES ON CORAL REEF FLATS AND IN ATOLL LAGOONS

The following sections are included:

• INTRODUCTION

• CLASSIFICATION OF ESTUARIES
  • Estuary geomorphology
  • Classification by salinity structure

• DENSITY DRIVEN FLOWS AND STRATIFICATION
  • Density variation
  • Flow forcing from density differences
  • Stratification and restratification
  • Stratified fluids in motion
  • Shear instability at an interface
  • Mixing or entrainment across an interface
  • Turbidity currents and saline underflows

• DISPERSION PROCESSES
  • Concentration distributions and their statistics
  • Flux and flux density
  • Advective dispersion
  • Gradient diffusion and the diffusion equation
  • Advection diffusion
  • The random walk analogy of turbulence and turbulent mixing
  • The mixing length approach to turbulent diffusion
  • Apparent Fickian diffusivities
  • Fickian approximations to turbulent diffusion
  • Dispersion due to combined shear, advection and diffusion
  • Dispersion in oscillatory shear flow

The following sections are included:

• INTRODUCTION

• BED SHEAR STRESSES
  • Introduction
  • The log law for steady flow
  • The wave friction factor
  • Time dependent bed shear stresses

• SEDIMENT MOBILITY
  • Introduction
  • Sediment characteristics
  • Forces on sediment particles
  • The mobility number
  • The Shields parameter
  • Infiltration effects
  • Initiation of sediment motion

• BEDLOAD AND SHEET FLOW
  • Introduction
  • What is bedload?
  • Dispersive stress and the amount of bedload
  • Meyer-Peter type bedload formulae
  • The typical speed of the bedload
  • Energy dissipation and bedload
  • Velocity moment formulae
  • Bedload and sheetflow transport in an arbitrary flow

• BEDFORMS AND HYDRAULIC ROUGHNESS
  • Introduction
  • Bedform dynamics
    • Observations of migrating natural bedforms
    • The continuity equation
    • Bedforms migrating with constant form
    • Migration and growth of sinusoidal bedforms
    • Numerical issues in bed updating
  • Vortex ripples
  • Megaripples
  • Bedforms in combined wave current flows
  • Hydraulic roughness

• THE MOTION OF SUSPENDED PARTICLES
  • Introduction
  • Equation of motion for a suspended particle or bubble
  • The time scale of particle acceleration
  • Suspended particles in wave flows
  • Suspended particles in vortices
  • Turbulence effects on settling of particles and rise of bubbles
  • Reduced particle velocity variance due to selective sampling

• SEDIMENT SUSPENSIONS
  • Introduction
  • The modelling framework for sediment suspensions
  • Reference concentrations
  • Pickup functions
  • Sediment distribution modelling
    • The mixing length approach
    • Mixing length model of u(z) and c(z) for l_m = λ_Z and W_m = γu
    • Suspension under waves
  • Suspensions of cohesive sediments

• BASIC SEDIMENT TRANSPORT MODEL BUILDING
  • Introduction
  • Two different families of transport models

• SEDIMENT TRANSPORT OUTSIDE THE SURF ZONE
  • Shorenormal transport
  • Shoreparallel transport outside the surf zone

• SURF ZONE SEDIMENT TRANSPORT
  • Shorenormal transport
  • Shoreparallel transport

• SWASH ZONE SEDIMENT TRANSPORT
  • Swash sediment transport and the beach watertable

• CONCLUDING REMARKS ON SEDIMENT TRANSPORT MODELLING

The following sections are included:

• INTRODUCTION

• BEACH PROFILES
  • “Equilibrium profile shape”
  • Profile shape variability
  • Tide range influence on beach morphology
  • Depth of closure
  • Storm erosion and time scales of profile change
  • Bars

• BEACH PLAN-FORMS

• SEDIMENT BUDGETS
  • The 2D vertical sediment budget
  • Bruun's rule for shoreline retreat due to sea-level rise
  • 3D sediment budgets
  • Lee side erosion
  • Beach realignment due to climate change

• MORPHOLOGY OF TIDAL INLETS

• DELTAS

• CORAL CAYS AND ATOLLS

The following sections are included:

• INTRODUCTION

• QUASI-STEADY EFFECTS OF WAVES AND TIDES ON THE INLAND WATERTABLE

• WATERTABLE VARIATION AND WATER EXCHANGE AT THE BEACH FACE
  • Pressure fluctuations under the beach face

• WATERTABLE WAVES
  • Shallow aquifer, small amplitude and no capillary effects
  • Capillary effects, partial saturation and effective porosity
  • Shallow aquifer, finite amplitude
  • Finite aquifer depth, small amplitude

The following sections are included:

• References

• Index