RiversintheLandscape Rivers in the Landscape EllenWohl ColoradoStateUniversity FortCollins,CO,USA SecondEdition Thissecondeditionfirstpublished2020 ©2020JohnWiley&SonsLtd EditionHistory Wiley-Blackwell(1e,2014) Allrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmitted,inanyformor byanymeans,electronic,mechanical,photocopying,recordingorotherwise,exceptaspermittedbylaw.Adviceonhowto obtainpermissiontoreusematerialfromthistitleisavailableathttp://www.wiley.com/go/permissions. TherightofEllenWohltobeidentifiedastheauthorofthisworkhasbeenassertedinaccordancewithlaw. RegisteredOffice(s) JohnWiley&Sons,Inc.,111RiverStreet,Hoboken,NJ07030,USA JohnWiley&SonsLtd,TheAtrium,SouthernGate,Chichester,WestSussex,PO198SQ,UK EditorialOffice 9600GarsingtonRoad,Oxford,OX42DQ,UK Fordetailsofourglobaleditorialoffices,customerservices,andmoreinformationaboutWileyproductsvisitusatwww .wiley.com. 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LibraryofCongressCataloging-in-PublicationData Names:Wohl,EllenE.,1962-author. Title:Riversinthelandscape/EllenWohl. Description:Secondedition.|Hoboken,NJ:JohnWiley&Sons,Inc.,2020. |Includesbibliographicalreferencesandindex. Identifiers:LCCN2019032034(print)|LCCN2019032035(ebook)|ISBN 9781119535416(paperback)|ISBN9781119535478(adobepdf)|ISBN 9781119535430(epub) Subjects:LCSH:Rivers–Research.|Fluvialgeomorphology–Research. Classification:LCCGB1201.7.W652020(print)|LCCGB1201.7(ebook)| DDC551.48/3–dc23 LCrecordavailableathttps://lccn.loc.gov/2019032034 LCebookrecordavailableathttps://lccn.loc.gov/2019032035 CoverDesign:Wiley CoverImage:CourtesyofEllenWohl Setin10/12ptWarnockProbySPiGlobal,Chennai,India 10 9 8 7 6 5 4 3 2 1 v Contents Acknowledgements xi 1 Introduction 1 1.1 ConnectivityandInequality 3 1.2 SixDegreesofConnection 8 1.3 RiversasIntegrators 11 1.4 OrganizationofthisVolume 13 1.5 UnderstandingRivers 15 1.5.1 TheColoradoFrontRange 15 1.6 OnlyConnect 26 2 CreatingChannelsandChannelNetworks 27 2.1 GeneratingWater,Solutes,andSediment 27 2.1.1 GeneratingWater 27 2.1.2 GeneratingSedimentandSolutes 28 2.2 GettingWater,Solutes,andSedimentDownslopetoChannels 30 2.2.1 DownslopePathwaysofWater 30 2.2.2 DownslopeMovementofSediment 39 2.2.3 ProcessesandPatternsofWaterChemistryEnteringChannels 42 2.2.4 InfluenceoftheRiparianZoneonFluxesintoChannels 43 2.3 HumanInfluencesonFluxesfromUplandstoChannels 46 2.3.1 ClimateChange 46 2.3.2 AlteredLandCover 48 2.3.2.1 Deforestation 48 2.3.2.2 Afforestation 49 2.3.2.3 Grazing 50 2.3.2.4 CropGrowth 50 2.3.2.5 Urbanization 50 2.3.2.6 UplandMining 51 2.3.2.7 LandDrainage 52 2.3.2.8 CommercialRecreationalPropertyDevelopment 52 2.4 ChannelInitiation 53 2.5 ExtensionandDevelopmentoftheDrainageNetwork 57 vi Contents 2.5.1 MorphometricIndicesandScalingLaws 58 2.5.2 Optimality 61 2.6 SpatialDifferentiationWithinDrainageBasins 62 2.7 Summary 64 PartI ChannelProcessesI 67 3 WaterDynamics 69 3.1 Hydraulics 69 3.1.1 FlowClassification 70 3.1.2 Energy,FlowState,andHydraulicJumps 74 3.1.3 UniformFlowEquationsandFlowResistance 76 3.1.4 VelocityandTurbulence 86 3.1.5 MeasuresofEnergyExertedAgainsttheChannelBoundaries 93 3.1.6 NumericalModelsofHydraulics 94 3.2 Hydrology 95 3.2.1 MeasuringDischarge 95 3.2.2 IndirectlyEstimatingDischarge 96 3.2.3 ModelingDischarge 103 3.2.4 FloodFrequencyAnalysis 105 3.2.5 HydrographsandFlowRegime 106 3.2.6 OtherParametersUsedtoCharacterizeDischarge 110 3.2.7 HyporheicExchangeandHydrology 110 3.2.8 RiverHydrologyinColdRegions 114 3.2.9 HumanInfluencesonHydrology 115 3.2.9.1 FlowRegulation 115 3.2.9.2 RiverCorridorEngineering 122 3.2.10 TheNaturalFlowRegime 123 3.3 Summary 124 PartII ChannelProcessesII 125 4 FluvialSedimentDynamics 127 4.1 TheChannelBedandInitiationofMotion 128 4.1.1 BedSedimentCharacterization 128 4.1.2 EntrainmentofNoncohesiveSediment 129 4.1.2.1 ForcesActingonaGrain 131 4.1.2.2 GrainProperties 133 4.1.2.3 Turbulence 134 4.1.2.4 BioticProcesses 134 4.1.3 ErosionofCohesiveBeds 135 4.1.3.1 ErosionofBedrock 135 4.1.3.2 ErosionofCohesiveSediment 139 Contents vii 4.2 SedimentTransport 139 4.2.1 DissolvedLoad 139 4.2.1.1 Nitrogen 141 4.2.1.2 Carbon 141 4.2.1.3 TraceMetals 143 4.2.1.4 OtherEnvironments 144 4.2.2 SuspendedLoad 144 4.2.3 BedLoad 151 4.2.3.1 BedLoadinChannelswithCoarse-GrainedSubstrate:CoarseSurfaceLayer 152 4.2.3.2 BedLoadinChannelswithCoarse-GrainedSubstrate:CharacteristicsofGrain Movements 154 4.2.3.3 BedLoadinChannelswithCoarse-GrainedSubstrate:ControlsonBed-Load Dynamics 156 4.2.3.4 EstimatingBed-LoadFlux 158 4.2.3.5 FieldMeasurementsofBedLoad 161 4.3 Bedforms 163 4.3.1 ReadilyMobileBedforms 163 4.3.2 InfrequentlyMobileBedforms 167 4.3.2.1 ParticleClusters 167 4.3.2.2 TransverseRibs 167 4.3.2.3 SteepAlluvialChannelBedforms 168 4.3.2.4 Step–PoolChannels 169 4.3.2.5 Pool–RiffleChannels 171 4.3.2.6 Bars 175 4.3.3 BedformsinCohesiveSediments 175 4.4 In-ChannelDepositionalProcesses 176 4.5 DownstreamTrendsinGrainSize 178 4.6 BankStabilityandErosion 179 4.7 SedimentBudgets 184 4.8 HumanInfluencesonSedimentDynamics 189 4.9 TheNaturalSedimentRegime 193 4.10 Summary 194 PartIII ChannelProcessesIII 197 5 LargeWoodDynamics 199 5.1 TheContinuumofVegetationinRiverCorridors 199 5.2 RecruitmentofWoodtoRiverCorridors 201 5.3 WoodEntrainmentandTransport 203 5.4 WoodDeposition 207 5.5 WoodStorage 208 5.6 WoodInteractionswithWaterandSediment 212 5.7 HumanInfluencesonWoodDynamics 215 5.8 TheNaturalWoodRegime 216 5.9 Summary 218 viii Contents 6 ChannelForms 219 6.1 Cross-SectionalGeometry 220 6.1.1 Bankfull,Dominant,andEffectiveDischarge 220 6.1.2 Width-to-DepthRatio 222 6.1.3 HydraulicGeometry 223 6.1.3.1 At-A-StationHydraulicGeometry 223 6.1.3.2 DownstreamHydraulicGeometry 225 6.1.4 Lane’sBalance 226 6.1.5 ComplexResponse 228 6.1.6 ChannelEvolutionModels 228 6.2 ChannelPlanform 231 6.2.1 StraightChannels 232 6.2.2 MeanderingChannels 233 6.2.3 WanderingChannels 238 6.2.4 BraidedChannels 239 6.2.5 AnabranchingChannels 244 6.2.6 CompoundChannels 246 6.2.7 KarstChannels 246 6.2.8 ContinuumConcept 246 6.2.9 RiverMetamorphosis 247 6.3 Confluences 250 6.4 BedrockChannels 254 6.5 RiverGradient 255 6.5.1 LongitudinalProfile 257 6.5.2 StreamGradientIndex 261 6.5.3 Knickpoints 262 6.6 AdjustmentofChannelForm 265 6.6.1 ExtremalHypothesesofChannelAdjustment 266 6.6.2 NonlinearBehaviorandAlternativeStates 267 6.6.3 GeomorphicEffectsofFloods 268 6.7 HumanInfluencesonChannelForm 270 6.8 Summary 276 7 Extra-ChannelEnvironments 277 7.1 Floodplains 277 7.1.1 FloodplainFunctions 278 7.1.2 FloodplainHydrology 281 7.1.3 DepositionalProcessesandFloodplainStratigraphy 281 7.1.4 ErosionalProcessesandFloodplainTurnoverTimes 287 7.1.5 DownstreamTrendsinFloodplainFormandProcess 289 7.1.6 ClassificationofFloodplains 290 7.1.7 HumanInfluencesonFloodplains 290 7.2 Terraces 291 7.2.1 TerraceClassifications 292 7.2.2 MechanismsofTerraceFormationandPreservation 295 Contents ix 7.2.3 TerracesasPaleoprofilesandPaleoenvironmentalIndicators 297 7.3 AlluvialFans 300 7.3.1 ErosionalandDepositionalProcesses 302 7.3.2 FanGeometryandStratigraphy 303 7.3.3 Mapping,Studying,andLivingonFans 305 7.4 Deltas 306 7.4.1 ProcessesofErosionandDeposition 308 7.4.2 DeltaMorphologyandStratigraphy 309 7.4.3 PaleoenvironmentalRecords 312 7.4.4 DeltasintheAnthropocene 313 7.5 Estuaries 314 7.6 Summary 316 8 RiversintheLandscape 319 8.1 RiversandTopography 319 8.1.1 Tectonics,Topography,andLargeRivers 321 8.1.2 IndicatorsofRelationsBetweenRiversandLandscapeEvolution 323 8.1.3 TectonicInfluencesonRiverGeometry 323 8.1.4 EffectsofRiverIncisiononTectonics 324 8.1.5 Bedrock-ChannelIncisionandLandscapeEvolution 325 8.2 ClimaticSignatures 328 8.2.1 HighLatitudes 328 8.2.2 LowLatitudes 331 8.2.3 WarmDrylands 333 8.3 SpatialDifferentiationAlongaRiver 336 8.4 Connectivity 338 8.5 RiverManagementinanEnvironmentalContext 342 8.5.1 ReferenceConditions 342 8.5.2 Restoration 344 8.5.3 Instream,ChannelMaintenance,andEnvironmentalFlows 350 8.5.4 RiverHealth 353 8.6 RiverswithaHistory 355 8.7 TheGreaterContext 357 References 361 Index 491 xi Acknowledgements The contents of this book reflect the contributions of many individuals. Mike Church helped to explain the evolution of thinking about bedload transport. Bill Dietrich identified pioneering dis- cussions of bedload dynamics in G.K. Gilbert’s flume experiments. Angela Gurnell helped me to more fully integrate plants into my thinking about river process and form. Theodore Endreny and GrantMeyerhelpedmetoidentifyandcorrecterrorsinthefirsteditionofthebook.NatalieKramer, KatherineLininger,LinaPolvi,andDanScottprovidedstimulatingdiscussionsaboutvariousaspects ofriverscience.Ithankeachofthemandmanyothercolleagueswhohavemadethestudyofrivers suchanenjoyablechallenge.