Tidal Inlets: Hydrodynamics and Morphodynamics

187 Pages·2017·30.086 MB·English

by  J. van de Kreeke, R. L. Brouwer

TIDAL INLETS
HydrodynamicsandMorphodynamics
This book describes the latest developments in the hydrodynamics and mor-
phodynamics of tidal inlets, with an emphasis on natural inlets. A review of
morphological features and sand transport pathways is presented, followed by an
overview of empirical relationships between inlet cross-sectional area, ebb delta
volume, flood delta volume and tidal prism. Results of field observations and lab-
oratory experiments are discussed and simple mathematical models are presented
that calculate the inlet current and basin tide. The method to evaluate the cross-
sectional stability of inlets, proposed by Escoffier, is reviewed, and is expanded,
forthefirsttime,toincludedoubleinletsystems.Thisvolumeisanidealreference
forcoastalscientists,engineersandresearchers,inthefieldsofcoastalengineering,
geomorphology,marinegeologyandoceanography.
J. VAN DE KREEKE is Emeritus Professor at the Rosenstiel School of Marine
and Atmospheric Science, University of Miami, where his research focused on
coastalengineeringandestuarineandnearshorehydrodynamics.Hehaspublished
extensively on tidal inlets, and is the editor of Physics of Shallow Estuaries and
Bays (Springer-Verlag, 1986). In 2004, Professor van de Kreeke received the Bob
DeanCoastalResearchAwardforworld-renownedresearchontidalinlets.
R.L. BROUWER, while at Delft University of Technology, The Netherlands,
wrote both his MSc and PhD theses on the subject of cross-sectional stability of
doubleinletsystems.Hecontinuedworkingonthissubjectasapostdoctoralfellow
andatthesametimedidpioneeringworkindeployingdronesforcoastalandinlet
research.Hehaspublishedseveralpapersondoubleinletsystemsinrefereedjour-
nals and conference proceedings. Presently, he is employed as a senior researcher
atFlandersHydraulicResearchinAntwerp,Belgium.

TIDAL INLETS
Hydrodynamics and Morphodynamics
J. VAN DE KREEKE
UniversityofMiami,USA
and
R.L. BROUWER
DelftUniversityofTechnology,TheNetherlands
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www.cambridge.org
Informationonthistitle:www.cambridge.org/9781107194410
DOI:10.1017/9781108157889
(cid:2)c J.vandeKreekeandR.L.Brouwer2017
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andtotheprovisionsofrelevantcollectivelicensingagreements,
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Firstpublished2017
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Contents
Preface pagexi
1 Introduction 1
2 Geomorphology 6
2.1 Introduction 6
2.2 OriginofTidalInlets 6
2.3 EquilibriumMorphology 7
2.4 Large-ScaleMorphologicalElements 8
2.4.1 Inlet 8
2.4.2 EbbDelta 9
2.4.3 FloodDelta 11
2.5 Back-BarrierLagoon 11
3 SandTransportPathways 13
3.1 Introduction 13
3.2 SedimentBudget 14
3.3 SandBypassing 16
3.3.1 BypassingModes 16
3.3.2 BypassingModesandtheP/M Ratio 17
3.4 InletClosure 19
3.5 LocationStability 19
3.6 EffectofInletsonAdjacentShoreline 20
3.6.1 ContinuousBypassing 20
3.6.2 IntermittentBypassing 21
4 SandTransportandSandBypassingatSelectedInlets 24
4.1 Introduction 24
4.2 PriceInlet 24
v
vi Contents
4.3 BreachInlet 25
4.4 CaptainSam’sInlet 26
4.5 MasonInlet 28
4.6 WachapreagueInlet 29
4.7 KatikatiInlet 30
4.8 AmelandInlet 31
5 EmpiricalRelationships 34
5.1 Introduction 34
5.2 Cross-SectionalArea–TidalPrismRelationship 34
5.2.1 Observations 34
5.2.2 PhysicalJustificationoftheA–PRelationship 35
5.2.3 ExamplesofA–PRelationshipsforNaturalInlets 37
5.2.4 EquilibriumVelocity 40
5.3 Relationship between Depth and Width of the
Cross-SectionandTidalPrism 40
5.4 EbbDeltaVolume–TidalPrismRelationship 41
5.5 FloodDeltaVolume–TidalPrismRelationship 43
6 TidalInletHydrodynamics;ExcludingDepthVariationswith
TidalStage 44
6.1 Introduction 44
6.2 InletSchematization 44
6.3 GoverningEquationsandBoundaryCondition 44
6.3.1 DimensionalEquations 44
6.3.2 Non-DimensionalEquations;LumpedParameterModel 46
6.4 AnalyticalSolution(Öszoy–Mehta) 47
6.4.1 BasinTideandInletVelocity 47
6.4.2 NatureoftheSolution;Resonance 49
6.5 Semi-AnalyticalSolution(Keulegan) 50
6.5.1 BasinTideandInletVelocity 50
6.5.2 MaximumBasinLevelandMaximumInletVelocity 53
6.5.3 RelativeContributionoftheThirdHarmonic 54
6.5.4 MultipleInlets 54
6.6 ApplicationtoaRepresentativeTidalInlet 55
6.6.1 RepresentativeTidalInlet 55
6.6.2 Öszoy–MehtaSolution 55
6.6.3 KeuleganSolution 57
6.A DynamicsoftheFlowintheInlet 58
Contents vii
7 TidalInletHydrodynamics;IncludingDepthVariationswith
TidalStage 61
7.1 Introduction 61
7.2 EquationsIncludingDepthVariationswithTidalStage 61
7.3 SolutionoftheLeading-OrderEquations 63
7.4 SolutiontotheFirst-OrderEquations 65
7.4.1 First-OrderForcing 65
7.4.2 MeanInletVelocityandMeanBasinLevel 66
7.4.3 First-OrderTideandVelocity 67
7.5 TidalAsymmetry 69
7.6 ApplicationtotheRepresentativeInlet 70
7.6.1 Leading-OrderSolution 70
7.6.2 First-OrderSolution 72
7.6.3 TidalAsymmetry 72
7.A ReducedSystemofEquationsandPerturbationAnalysis 73
8 Cross-SectionalStabilityofaSingleInletSystem 75
8.1 Introduction 75
8.2 EquilibriumandStability 75
8.2.1 EscoffierStabilityModel 75
8.2.2 EscoffierDiagram 76
8.2.3 TheShapeoftheClosureCurve 77
8.3 AdaptationTimescale 78
8.4 Cross-SectionalStabilityofPassCavallo 80
8.A GeometricSimilarity 82
8.B LinearStabilityAnalysis 84
9 Cross-SectionalStabilityofaDoubleInletSystem,Assuming
aUniformlyVaryingBasinWaterLevel 86
9.1 Introduction 86
9.2 EscoffierStabilityModelforaDoubleInletSystem 87
9.2.1 Schematization 87
9.2.2 EquilibriumVelocity 88
9.2.3 GoverningEquations 89
9.2.4 ClosureSurface 90
9.2.5 EquilibriumVelocityCurves 90
9.2.6 FlowDiagram 91
9.3 ConditionsforaSetofStableCross-SectionalAreas 93
9.4 BasinwithTopographicHigh 95
9.4.1 Schematization 95
viii Contents
9.4.2 GoverningEquations 96
9.4.3 FlowDiagrams 97
10 Cross-SectionalStabilityofaDoubleInletSystem,Assuming
aSpatiallyVaryingBasinWaterLevel 100
10.1 Introduction 100
10.2 Schematization 100
10.3 GoverningEquationsandBoundaryConditions 100
10.4 SolutionMethod 103
10.5 Effect of Spatial Variations in Basin Water Level on
Cross-SectionalStability 104
10.5.1 SpatialVariationsinBasinWaterLevel 104
10.5.2 ComparisonwithEarlierStabilityAnalysis 105
10.5.3 Effects of Basin Depth, Coriolis Acceleration,
RadiationDampingandBasinGeometry 106
10.6 MultipleInlets 109
11 Morphodynamic Modeling of Tidal Inlets Using a
Process-BasedSimulationModel 110
11.1 Introduction 110
11.2 ModelConceptandFormulation 110
11.3 MorphologyofaNewlyOpenedInlet 112
11.4 Cross-SectionalArea–TidalPrismRelationship 115
11.5 LimitationsofProcess-BasedMorphodynamicModels 118
12 MorphodynamicModelingofTidalInletsUsingan
EmpiricalModel 120
12.1 Introduction 120
12.2 ModelingConcepts 120
12.3 EbbDeltaDevelopmentatOceanCityInlet 121
12.3.1 OceanCityInlet 121
12.3.2 SchematizationandModelFormulation 121
12.3.3 ModelResults 123
12.4 AdaptationoftheFrisianInletafterBasinReduction 124
12.4.1 FrisianInlet 124
12.4.2 SchematizationandModelFormulation 125
12.4.3 ModelResults 128
12.4.4 AnalyticalSolution;LocalandSystemTimescales 130
12.4.5 BumpsandOvershoots 134
Contents ix
12.5 Adaptation of an Inlet-Delta System Using a Diffusive
TransportFormulation 135
12.6 LimitationsofEmpiricalModeling 138
13 RiverFlowandEntranceStability 139
13.1 Introduction 139
13.2 EffectofRiverFlowonBasinTideandInletVelocity 140
13.3 Effect of River Flow on Cross-Sectional Stability of
SelectedInlets 143
13.3.1 ThuanAnInlet:APermanentlyOpenInlet 143
13.3.2 WilsonInlet:ASeasonallyOpenInlet 145
13.3.3 LakeConjolaInlet:AnIntermittentlyOpenInlet 145
13.4 AMorphodynamicModelfortheLong-TermEvolutionof
anInlet 147
13.A Öszoy–MehtaSolutionIncludingRiverFlow 150
14 EngineeringofTidalInlets 152
14.1 Introduction 152
14.2 ArtificialOpeningofaNewInlet 152
14.3 RelocationofanExistingInlet 155
14.4 Dredging 156
14.5 SandBypassingPlants 156
14.6 Jetties;JettyLengthandOrientation 158
14.7 Weir-JettySystems 160
References 161
Index 172