Fluvial Geomorphology.pdf

Embed Size (px)

Citation preview

  • 7/26/2019 Fluvial Geomorphology.pdf

    1/84

    11

    A STUDY OF FLUVIAL GEOMORPHOLOGY

    ASPECTS OF HYDRAULIC DESIGN

    A STUDY OF FLUVIAL GEOMORPHOLOGY

    ASPECTS OF HYDRAULIC DESIGN

    A. David Parr, Ph.D.and John Shelley

    CEAE DepartmentUniversity of Kansas

    (Funded by KDOT)

    A. David Parr, Ph.D.and John Shelley

    CEAE DepartmentUniversity of Kansas

    (Funded by KDOT)

  • 7/26/2019 Fluvial Geomorphology.pdf

    2/84

    22

    Jim Richardson

    Brad Rognlie

    Mike Orth

    KDOT Bridge Section

    Jim RichardsonJim Richardson

    Brad RognlieBrad Rognlie

    Mike OrthMike Orth

    KDOT Bridge SectionKDOT Bridge Section

    AcknowledgmentsAcknowledgments

  • 7/26/2019 Fluvial Geomorphology.pdf

    3/84

    33

    Stable Channel DesignStable Channel DesignStable Channel DesignKDOT is sometimes required to realign

    short reaches of alluvial channels to

    facilitate highway improvements or toprovide protection for highway structuresor roadway embankments.

    The new stream reaches should be dynamicallystable and should have geomorphic properties thatare characteristic of natural streams in similar

    settings.

    They should also be hydraulically and ecologicallycompatible with the contiguous upstream anddownstream stream reaches.

    KDOT is sometimes required to realignKDOT is sometimes required to realignshort reaches of alluvial channels toshort reaches of alluvial channels to

    facilitate highway improvements or tofacilitate highway improvements or toprovide protection for highway structuresprovide protection for highway structuresor roadway embankments.or roadway embankments.

    The new stream reaches should be dynamicallyThe new stream reaches should be dynamicallystable and should have geomorphic properties thatstable and should have geomorphic properties thatare characteristic of natural streams in similarare characteristic of natural streams in similarsettings.settings.

    They should also be hydraulically and ecologicallyThey should also be hydraulically and ecologicallycompatible with the contiguous upstream andcompatible with the contiguous upstream anddownstream stream reaches.downstream stream reaches.

  • 7/26/2019 Fluvial Geomorphology.pdf

    4/84

    44

    Stream Modification - Road ProjectStream ModificationStream Modification -- Road ProjectRoad Project

    Old RoadOld Road

    Old StreamOld Stream

    New StreamNew Stream

    New RoadNew Road

    (b)(b)

    (a)(a)

  • 7/26/2019 Fluvial Geomorphology.pdf

    5/84

    55

    Protection - Meanders on the Kansas RiverProtection - Meanders on the Kansas River

    (a)

    (b)

  • 7/26/2019 Fluvial Geomorphology.pdf

    6/84

  • 7/26/2019 Fluvial Geomorphology.pdf

    7/84

    77

    Bank-full Discharge ConditionsBankBank--full Discharge Conditionsfull Discharge Conditions

    Copeland* states Bank-full discharge is

    the maximum discharge that a steam can

    convey without overflowing into the

    floodplain. The water surface elevation

    for this condition is called the bank-fullstage.

    Bank-full discharge is also referred to asthe channel-forming discharge.

    Copeland* statesCopeland* states BankBank--full discharge isfull discharge is

    the maximum discharge that a steam canthe maximum discharge that a steam can

    convey without overflowing into theconvey without overflowing into the

    floodplainfloodplain.. The water surface elevationThe water surface elevation

    for this condition is called the bankfor this condition is called the bank--fullfullstage.stage.

    BankBank--full discharge is also referred to asfull discharge is also referred to asthethe channelchannel--forming dischargeforming discharge..

    *http://chl.erdc.usace.army.mil/library/publications/chetn/pdf/chetn-viii-5.pdf*http://chl.erdc.usace.army.mil/library/publications/chetn/pdf/chetn-viii-5.pdf

  • 7/26/2019 Fluvial Geomorphology.pdf

    8/84

    88

    Upstream Supply ReachUpstream Supply ReachUpstream Supply Reach

    Project SiteProject Site

    Flow

    Riffle on Stable Upstream

    Supply ReachRiffle on Stable Upstream

    Supply Reach

    Supply ReachCross SectionSupply ReachCross Section

    Sinuosity = Lstream/Lvalley

  • 7/26/2019 Fluvial Geomorphology.pdf

    9/84

    99

    Bankfull Conditions for Supply

    Reach Cross Section(1.2 to 2 year recurrence interval)

    Bankfull Conditions for SupplyBankfull Conditions for Supply

    Reach Cross SectionReach Cross Section((1.2 to 2 year recurrence interval)

    Wbf

    Abf

    dmax

    Wbf

    = bankfull width

    Abf= bankfull area

    dbf= Abf/Wbf= bankfull depth

    Bankfull

    Stage

  • 7/26/2019 Fluvial Geomorphology.pdf

    10/84

    1010

    Determination of Bank-full Stage(http://www.stockton.edu/~epsteinc/rosgen~1.htm)

    Determination of Bank-full Stage(http://www.stockton.edu/~epsteinc/rosgen~1.htm)

    Involves assessing the elevation wherethe channel, under bank-full dischargeconditions, ends and the floodplain begins.The indicators used to assess thiselevation are as follows:

    Top of the point bar

    A change in vegetation

    Slope change in channel cross section

    Top of the undercut slopeChange in particle size (where soils end andsediments begin),

    Drift lines and water marks

    Involves assessing the elevation wherethe channel, under bank-full dischargeconditions, ends and the floodplain begins.The indicators used to assess thiselevation are as follows:

    Top of the point bar

    A change in vegetation

    Slope change in channel cross section

    Top of the undercut slopeChange in particle size (where soils end andsediments begin),

    Drift lines and water marks

  • 7/26/2019 Fluvial Geomorphology.pdf

    11/84

    1111

    University of Kansas StudiesUniversity of Kansas StudiesUniversity of Kansas Studies

    Guidelines for Stream Realignment Design KAMMethod

    McEnroe, Young and ShelleyReport No. K-TRAN KU-08-2

    Stream Realignment Design using a ReferenceReach ARR Method

    McEnroe, Young and ShelleyReport No. K-TRAN KU-09-4

    A Study of Fluvial Geomorphology Aspects ofHydraulic Design (HEC-RAS applications)

    Parr and Shelley

    Report No. K-TRAN: KU-08-5

    Guidelines for Stream Realignment DesignGuidelines for Stream Realignment Design KAMKAMMethodMethod

    McEnroe, Young and ShelleyMcEnroe, Young and ShelleyReport No. KReport No. K--TRAN KUTRAN KU--0808--22

    Stream Realignment Design using a ReferenceStream Realignment Design using a ReferenceReachReach ARR MethodARR Method

    McEnroe, Young and ShelleyMcEnroe, Young and ShelleyReport No. KReport No. K--TRAN KUTRAN KU--0909--44

    A Study of Fluvial Geomorphology Aspects of

    Hydraulic Design (HEC-RAS applications)Parr and ShelleyParr and Shelley

    Report No. KReport No. K--TRAN: KUTRAN: KU--0808--55

    This StudyThis Study

  • 7/26/2019 Fluvial Geomorphology.pdf

    12/84

    1212

    KAM and ARR MethodsKAM and ARR MethodsKAM and ARR Methods

    Consider alluvial (noncohesive) and threshold(cohesive) channels.

    StrengthsInclude planform design for stream meanders and

    pool spacingDesigns pool depth

    Uses a simple version of the Meyer-Peter Mueller

    sediment transport equation for analytical methodsARR incorporates features of both analytical andreference reach methods

    Consider alluvial (noncohesive) and thresholdConsider alluvial (noncohesive) and threshold(cohesive) channels.(cohesive) channels.

    StrengthsStrengths

    Include planform design for stream meanders andInclude planform design for stream meanders and

    pool spacingpool spacingDesigns pool depthDesigns pool depth

    Uses a simple version of the MeyerUses a simple version of the Meyer--Peter MuellerPeter Mueller

    sediment transport equation for analytical methodssediment transport equation for analytical methodsARR incorporates features of both analytical andARR incorporates features of both analytical andreference reach methodsreference reach methods

  • 7/26/2019 Fluvial Geomorphology.pdf

    13/84

    1313

    KAM and ARR Methods (Cont.)KAM and ARR Methods (Cont.)KAM and ARR Methods (Cont.)

    Limitations

    Plane bed (no bedforms)

    Wide channels (Large width to depthratios)

    No consideration of grain sizedistribution other than d50Does not allow for separation of bedand bank hydraulic roughness

    LimitationsLimitations

    Plane bed (no bedforms)Plane bed (no bedforms)

    Wide channels (Large width to depthWide channels (Large width to depthratios)ratios)

    No consideration of grain sizeNo consideration of grain sizedistribution other than ddistribution other than d5050Does not allow for separation of bedDoes not allow for separation of bedand bank hydraulic roughnessand bank hydraulic roughness

  • 7/26/2019 Fluvial Geomorphology.pdf

    14/84

    1414

    Study ObjectivesStudy ObjectivesStudy ObjectivesDevelop procedures to use HEC-RAS 4.0 in the

    design of stable channel reaches for alluvial

    streams using the Analytical Approach.

    Provide examples for streams with

    Sand beds

    Gravel/cobble beds.

    Compare HEC-RAS methods with McEnroesKAM and ARR Methods.

    Develop procedures to use HECDevelop procedures to use HEC--RAS 4.0 in theRAS 4.0 in thedesign of stable channel reaches for alluvialdesign of stable channel reaches for alluvial

    streams using thestreams using theAnalytical ApproachAnalytical Approach..

    Provide examples for streams withProvide examples for streams with

    Sand bedsSand beds

    Gravel/cobble beds.Gravel/cobble beds.

    Compare HECCompare HEC--RAS methods with McEnroeRAS methods with McEnroessKAM and ARR Methods.KAM and ARR Methods.

  • 7/26/2019 Fluvial Geomorphology.pdf

    15/84

    1515

    Stable Channel Design in HEC-RASStable Channel Design in HECStable Channel Design in HEC--RASRAS

    Uses Steady Flow modeling to determine parameters

    needed for the sediment transport modeling components.

    Velocity

    DepthArea

    Only Mannings n-values can be used in the HEC-RAS

    steady flow model for resistance.

    Uses Hydraulic Design Functions to perform uniform flow

    and sediment transport capacity calculations. Brownlie,

    Strickler, Limerinos and Manning equations can be usedto account for channel resistance. Brownlie and

    Limerinos resistance equations account for bed form

    resistance as well as resistance due to grains.

    UsesUses Steady FlowSteady Flow modeling to determine parametersmodeling to determine parameters

    needed for the sediment transport modeling components.needed for the sediment transport modeling components.

    VelocityVelocity

    DepthDepthAreaArea

    Only ManningOnly Mannings ns n--values can be used in the HECvalues can be used in the HEC--RASRAS

    steady flow model for resistance.steady flow model for resistance.

    UsesUses Hydraulic Design FunctionsHydraulic Design Functions to perform uniform flowto perform uniform flow

    and sediment transport capacity calculations. Brownlie,and sediment transport capacity calculations. Brownlie,

    Strickler, Limerinos and Manning equations can be usedStrickler, Limerinos and Manning equations can be usedto account for channel resistance. Brownlie andto account for channel resistance. Brownlie and

    Limerinos resistance equations account for bed formLimerinos resistance equations account for bed form

    resistance as well as resistance due to grains.resistance as well as resistance due to grains.

  • 7/26/2019 Fluvial Geomorphology.pdf

    16/84

    1616

    HEC-RAS Hydraulic Design

    Functions used in Analytical Design

    HECHEC--RAS Hydraulic DesignRAS Hydraulic Design

    Functions used in Analytical DesignFunctions used in Analytical Design

    Stable Channel Design

    Uniform Flow

    Sediment Transport Capacity

    Stable Channel DesignStable Channel Design

    Uniform FlowUniform Flow

    Sediment Transport CapacitySediment Transport Capacity

    Sand BedsSand Beds

    Gravel/Cobble BedsGravel/Cobble Beds

  • 7/26/2019 Fluvial Geomorphology.pdf

    17/84

    1717

    Resistance Formulas Used

    in

    Hydraulic Design Functions

    Resistance Formulas UsedResistance Formulas Used

    inin

    Hydraulic Design FunctionsHydraulic Design Functions

  • 7/26/2019 Fluvial Geomorphology.pdf

    18/84

    1818

    HEC-RAS Resistance Formulas

    for Alluvial Channels

    HECHEC--RAS Resistance FormulasRAS Resistance Formulas

    for Alluvial Channelsfor Alluvial Channels

    Equation Applicability Strengths Limitations

    Manning All natural and artificialstreams.

    Easy to use and to understand.

    Required for HEC-RAS hydraulic

    modeling.

    Requires a high level of

    engineering judgment to

    choose an appropriate

    value from a table or from a

    book of reference streams.

    Stricker Cobble bed streamsdominated by grain sizefriction.

    Quantified the hydraulics lossesdue to grain size friction based on

    measurable parameters.

    Does not include losses dueto bed forms. May be

    unrealistically low.

    Limerinos Stream beds withsediment sizes from

    coarse sand to cobble

    under an upper flowregime.

    Includes losses due to both grain

    roughness and bedforms. Based

    on measurable parameters.

    Not applicable to other

    sediment sizes or to the

    lower regime flow.

    Brownlie Sand bed streams ofeither an upper or a

    lower regime.

    Includes losses due to both grain

    roughness and bedforms. Based

    on measurable parameters. Can be

    used for either the upper or the

    lower flow regime. Correlates with

    the Brownlie sediemnt transport

    function.

    Not applicable to other

    sediment sizes.

  • 7/26/2019 Fluvial Geomorphology.pdf

    19/84

    1919

    Mannings EquationManningMannings Equations Equation

    V= Mean Velocity in ft/sec,

    1.49 = coefficient for English Units (1.0 for Metric),n = Mannings n value,

    R = Hydraulic radius, ft. = Area/Wetted Perimeter,

    S = Slope of the Energy Grade Line.

    (Bed slope for uniform flow)

    V= Mean Velocity in ft/sec,V= Mean Velocity in ft/sec,

    1.49 = coefficient for English Units (1.0 for Metric),1.49 = coefficient for English Units (1.0 for Metric), n = Manningn = Mannings n value,s n value,

    R = Hydraulic radius, ft. = Area/Wetted Perimeter,R = Hydraulic radius, ft. = Area/Wetted Perimeter,

    S = Slope of the Energy Grade Line.S = Slope of the Energy Grade Line.

    (Bed slope for uniform flow)(Bed slope for uniform flow)

    2 /3 1/ 21.49n R S

    V=

  • 7/26/2019 Fluvial Geomorphology.pdf

    20/84

    2020

    Strickler EquationStrickler EquationStrickler Equation

    1/ 6

    s

    s

    Rn k

    k

    =

    50

    90

    , ,

    .

    0.0342

    0.0342

    s

    s

    where k Nikuradse equivalet sand roughness ft or m d

    for natural channels and d for riprap lined channels

    R Strickler function for natrual channelsk

    for velocity and stone size calculations in riprap chann

    = =

    = =

    =

    0.038

    els

    for discharge calculations in riprap channels

    R hydraulic radius

    ==

  • 7/26/2019 Fluvial Geomorphology.pdf

    21/84

    2121

    Limerinos EquationLimerinos EquationLimerinos Equation

    d84

    = the particle size, ft, for which 84% of thesediment mixture is finer. Data ranged from0.00328 to 0.820 ft (1.5 to 250 mm). BIG STUFF

    n = Mannings n value. Data ranged from 0.02 to

    0.10.

    R = Hydraulic radius, ft. Data ranged from 1 to 6ft (0.35 to 1.83 m).

    dd8484 = the particle size, ft, for which 84% of the= the particle size, ft, for which 84% of the

    sediment mixture is finer. Data ranged fromsediment mixture is finer. Data ranged from0.00328 to 0.820 ft (1.5 to 250 mm).0.00328 to 0.820 ft (1.5 to 250 mm). BIG STUFFBIG STUFF

    n = Manningn = Mannings n value. Data ranged from 0.02 tos n value. Data ranged from 0.02 to

    0.10.0.10.

    R = Hydraulic radius, ft. Data ranged from 1 to 6R = Hydraulic radius, ft. Data ranged from 1 to 6ft (0.35 to 1.83 m).ft (0.35 to 1.83 m).

    1/ 6

    10

    84

    0.0926

    1.16 2.0 log

    Rn

    Rd

    =

    +

  • 7/26/2019 Fluvial Geomorphology.pdf

    22/84

    2222

    Brownlie Resistance Equations

    Sand Only

    Brownlie Resistance EquationsBrownlie Resistance Equations

    Sand OnlySand Only

    d50 = the particle size, ft, for which 50% of thesediment mixture is finer by weight,

    s = the geometric standard deviation of the

    sediment mixture.

    dd5050 = the particle size, ft, for which 50% of the= the particle size, ft, for which 50% of thesediment mixture is finer by weight,sediment mixture is finer by weight,

    ss = the geometric standard deviation of the= the geometric standard deviation of the

    sediment mixture.sediment mixture.

    ( )

    ( )

    0.1374

    0.1670.1112 0.160550

    50

    0.0.6620.1670.0395 0.1282

    50

    50

    1.6940 0.034

    1.0213 0.034

    Lower Regime

    Rn S dd

    Upper Regime

    Rn S d

    d

    =

    =

  • 7/26/2019 Fluvial Geomorphology.pdf

    23/84

    2323

    Brownlie Resistance Equations

    (Cont.)

    Brownlie Resistance EquationsBrownlie Resistance Equations

    (Cont.)(Cont.)'

    ' '

    '

    '1/ 3

    50

    0.8 1.25

    0.006

    1.74

    ( 1)

    ( 2.65 )

    g g

    g g g

    g g

    g

    g

    s

    s

    Lower Regime F F

    Transition F F F

    Upper Regime S or F F

    FS

    VF grain Froude number

    s gdwhere

    s sediment specific gravity for sand

    =

    = =

    =

  • 7/26/2019 Fluvial Geomorphology.pdf

    24/84

    2424

    HEC-RAS

    Sediment Transport

    Equations

    HECHEC--RASRAS

    Sediment TransportSediment Transport

    EquationsEquations

  • 7/26/2019 Fluvial Geomorphology.pdf

    25/84

    2525

    Sand Beds - Brownlie SedimentTransport Equation

    Sand BedsSand Beds -- Brownlie SedimentBrownlie Sediment

    Transport EquationTransport Equation

    Used in the Stable Channel Hydraulic Design

    Function for sand bed channels only. Themethod is called the Copeland Method.

    Based on dimensional analysis and regressionof a very large body of field and laboratorysediment transport data for sand beds.

    Only applied to the movable bed does notconsider sediment transport from the mainchannel banks.

    Used in the Stable Channel Hydraulic DesignUsed in the Stable Channel Hydraulic Design

    Function forFunction for sand bed channels onlysand bed channels only. The. Themethod is called the Copeland Method.method is called the Copeland Method.

    Based on dimensional analysis and regressionBased on dimensional analysis and regressionof a very large body of field and laboratoryof a very large body of field and laboratorysediment transport data for sand beds.sediment transport data for sand beds.

    Only applied to the movable bedOnly applied to the movable bed does notdoes notconsider sediment transport from the mainconsider sediment transport from the mainchannel banks.channel banks.

  • 7/26/2019 Fluvial Geomorphology.pdf

    26/84

    2626

    Brownlie Sediment Transport Equation

    (Sand Bed Natural Channels)

    Brownlie Sediment Transport EquationBrownlie Sediment Transport Equation(Sand Bed Natural Channels)(Sand Bed Natural Channels)

    ( ) 0.33011.978 0.6601

    509022( ) /g goC F F S r d

    =

    ( )

    *

    50

    50

    0.5293 0.14

    / /

    4.596o

    g s

    go

    where C bed material concentration in ppm by weight

    r representative grain roughness height

    d geometric mean grain size of bed material

    S slope of energy grade line

    F V gd grain Froude number

    F S

    ==

    =

    =

    = =

    =

    ( )( )

    *

    05 0.1606

    7.7

    0.6

    3

    50

    0.22 0.06(10)

    /

    /

    o

    g

    Y

    g

    g s

    g

    critical grain Froude number

    Y critical shear stress

    geometric standard deviation of bed material

    Y R

    R gd grain Reynolds number

    =

    = + =

    =

    =

    = =

  • 7/26/2019 Fluvial Geomorphology.pdf

    27/84

    2727

    Gravel/Cobble Beds Sediment Transport

    Potential Functions

    Gravel/Cobble BedsGravel/Cobble Beds Sediment TransportSediment Transport

    Potential FunctionsPotential Functions

    Ackers-White

    Engelund-Hansen

    Laursen-Copeland

    Meyer-Peter Muller

    Toffaleti

    Yang

    AckersAckers--WhiteWhite

    EngelundEngelund--HansenHansen

    LaursenLaursen--CopelandCopeland

    MeyerMeyer--Peter MullerPeter Muller

    ToffaletiToffaleti

    YangYang

  • 7/26/2019 Fluvial Geomorphology.pdf

    28/84

    2828

    Ranges for Sediment Transport FunctionsRanges for Sediment Transport FunctionsRanges for Sediment Transport Functions

    dran

    ge,mm

    dran

    ge,mm

    Mean

    d,mm

    Mean

    d,mm

    Veloc

    ity,fps

    Veloc

    ity,fps

    Depth

    ,ft

    Depth

    ,ft

    Energ

    yGrad

    Energ

    yGrad

    Width

    ft

    Width

    ft

    Temp

    ,oF

    Temp

    ,oF

    Spec

    Gravity

    Spec

    Gravity

  • 7/26/2019 Fluvial Geomorphology.pdf

    29/84

    2929

    Sand Beds

    HEC-RAS Stable ChannelDesign

    Sand BedsSand Beds

    HECHEC--RAS Stable ChannelRAS Stable ChannelDesignDesign

  • 7/26/2019 Fluvial Geomorphology.pdf

    30/84

    3030

    HR Stable Channel DesignHR Stable Channel DesignHR Stable Channel Design

    Copeland Method using Brownlie Resistance

    and Sediment Transport Eqs.

    Sand Bed Channels Only.Resistance Due to Sidewall Roughness, Grains

    of the Bed Material and Bed Forms.

    Sediment Transport from Bed Only.

    Sidewall Roughness Method Applied.

    Does not specify channel plan form geometry or

    profile features. (See McEnroe KAM and ARR

    methods.)

    Copeland Method using Brownlie ResistanceCopeland Method using Brownlie Resistance

    and Sediment Transport Eqs.and Sediment Transport Eqs.

    Sand Bed Channels Only.Sand Bed Channels Only.Resistance Due to Sidewall Roughness, GrainsResistance Due to Sidewall Roughness, Grains

    of the Bed Material and Bed Forms.of the Bed Material and Bed Forms.

    Sediment Transport from Bed Only.Sediment Transport from Bed Only.

    Sidewall Roughness Method Applied.Sidewall Roughness Method Applied.

    Does not specify channel plan form geometry orDoes not specify channel plan form geometry or

    profile features. (See McEnroe KAM and ARRprofile features. (See McEnroe KAM and ARR

    methods.)methods.)

  • 7/26/2019 Fluvial Geomorphology.pdf

    31/84

    3131

    HR Stable Channel Design

    Requirements

    HR Stable Channel DesignHR Stable Channel Design

    RequirementsRequirements

    Upstream Supply Channel: (Trapezoidal channel

    geometry required.) Bottom width, depth,channel slope, side slopes, discharge,

    Mannings n for sidewalls, sediment gradation or

    sediment conc.Design Channel: Mannings n for sidewalls, side

    slopes, sediment gradation ,and either the

    bottom width, depth, or channel slope.Both: Need d16, d50 and d84

    Upstream Supply Channel:Upstream Supply Channel: (Trapezoidal channel(Trapezoidal channel

    geometry required.) Bottom width, depth,geometry required.) Bottom width, depth,channel slope, side slopes, discharge,channel slope, side slopes, discharge,

    ManningMannings n for sidewalls, sediment gradation ors n for sidewalls, sediment gradation or

    sediment conc.sediment conc.Design Channel:Design Channel: ManningMannings n for sidewalls, sides n for sidewalls, side

    slopes, sediment gradation ,and either theslopes, sediment gradation ,and either the

    bottom width, depth, or channel slope.bottom width, depth, or channel slope. Both:Both: Need dNeed d1616, d, d5050 and dand d8484

  • 7/26/2019 Fluvial Geomorphology.pdf

    32/84

    3232

    Procedure for Stable Channel Design of

    Sand Bed Channels

    Procedure for Stable Channel Design ofProcedure for Stable Channel Design of

    Sand Bed ChannelsSand Bed Channels Establish the bank-full properties of an upstream

    reference reach riffle cross section. Discharge, cross

    section geometry via station-elevation data, stage, bedmaterial (d16, d50 and d84), longitudinal energy grade line

    slope.

    Open the Uniform Flow function with the Manning for the

    bank resistance and Brownlie for the movable bed

    resistance. Input the slope and discharge. By iteration,

    determine the bank n-values needed to obtain the

    desired bank-full water surface elevation (stage) for thegiven bank-full discharge and slope.

    Establish the bankEstablish the bank--full properties of an upstreamfull properties of an upstream

    reference reach riffle cross section. Discharge, crossreference reach riffle cross section. Discharge, cross

    section geometry via stationsection geometry via station--elevation data, stage, bedelevation data, stage, bedmaterialmaterial ((dd1616, d, d5050 and dand d8484)), longitudinal energy grade line, longitudinal energy grade line

    slope.slope.

    Open the Uniform Flow function with the Manning for theOpen the Uniform Flow function with the Manning for the

    bank resistance and Brownlie for the movable bedbank resistance and Brownlie for the movable bed

    resistance. Input the slope and discharge. By iteration,resistance. Input the slope and discharge. By iteration,

    determine the bank ndetermine the bank n--values needed to obtain thevalues needed to obtain the

    desired bankdesired bank--full water surface elevation (stage) for thefull water surface elevation (stage) for thegiven bankgiven bank--full discharge and slope.full discharge and slope.

  • 7/26/2019 Fluvial Geomorphology.pdf

    33/84

    3333

    Procedure for Stable Channel Design of

    Sand Bed Channels (Cont.)

    Procedure for Stable Channel Design ofProcedure for Stable Channel Design of

    Sand Bed Channels (Cont.)Sand Bed Channels (Cont.)

    Using the bank n-values from the previous step,change the resistance formula for the bed to

    Manning then by iteration determine theappropriate n-value for the bed to obtain thedesired bankfull stage.

    Create an upstream supply reach that has threeof the natural channels using the bank and bedn-values determined above for the bankfullchannel.

    Run the HEC-RAS model.

    Using the bank nUsing the bank n--values from the previous step,values from the previous step,change the resistance formula for the bed tochange the resistance formula for the bed to

    Manning then by iteration determine theManning then by iteration determine theappropriate nappropriate n--value for the bed to obtain thevalue for the bed to obtain thedesired bankfull stage.desired bankfull stage.

    Create an upstream supply reach that has threeCreate an upstream supply reach that has threeof the natural channels using the bank and bedof the natural channels using the bank and bednn--values determined above for the bankfullvalues determined above for the bankfullchannel.channel.

    Run the HECRun the HEC--RAS model.RAS model.

  • 7/26/2019 Fluvial Geomorphology.pdf

    34/84

    3434

    Procedure for Stable Channel Design of

    Sand Bed Channels (Cont.)

    Procedure for Stable Channel Design ofProcedure for Stable Channel Design of

    Sand Bed Channels (Cont.)Sand Bed Channels (Cont.)

    Determine an equivalent trapezoidal channelthat has the same conveyance as the natural

    supply reach. Open the Stable Channel Designfunction.

    Input the side slopes, base width, bank n-values

    and the energy grade line slope of theequivalent upstream supply channel.

    Input the side slopes and bank n-values for thedesign channel.

    Run the Stable Channel Design model.

    Determine an equivalent trapezoidal channelDetermine an equivalent trapezoidal channelthat has the same conveyance as the naturalthat has the same conveyance as the natural

    supply reach. Open the Stable Channel Designsupply reach. Open the Stable Channel Designfunction.function.

    Input the side slopes, base width, bank nInput the side slopes, base width, bank n--valuesvalues

    and the energy grade line slope of theand the energy grade line slope of theequivalent upstream supply channel.equivalent upstream supply channel.

    Input the side slopes and bank nInput the side slopes and bank n--values for thevalues for thedesign channel.design channel.

    Run the Stable Channel Design model.Run the Stable Channel Design model.

    S d B d E l

  • 7/26/2019 Fluvial Geomorphology.pdf

    35/84

    3535

    Sand Bed ExampleSand Bed ExampleSand Bed Example

    49.021.6

    0

    5

    10

    15

    20

    25

    0 10 20 30 40 50 60 70 80

    Station (ft)

    Ele

    vation

    (ft)

    Sta-Elev Bankfull Elevation Movable Bed

    49.021.6

    0

    5

    10

    15

    20

    25

    0 10 20 30 40 50 60 70 80

    Station (ft)

    Elev

    ation

    (ft)

    Sta-Elev Bankfull Elevation Movable Bed

    2828 4444

    Bank-full Conditions

    d16, d50, d84 = 1.33, 2 and 3 mm, respectively

    Q = 325 cfsStage = 7 ft

    Slope = 0.00157

    BankBank--full Conditionsfull Conditions

    dd1616, d, d5050, d, d8484 = 1.33, 2 and 3 mm, respectively= 1.33, 2 and 3 mm, respectively

    Q = 325 cfsQ = 325 cfs Stage = 7 ftStage = 7 ft

    Slope = 0.00157Slope = 0.00157

    U if Fl ith Fi l M i lU if Fl ith Fi l M iU if Fl ith Fi l M i ll

  • 7/26/2019 Fluvial Geomorphology.pdf

    36/84

    3636

    Uniform Flow with Final Mannings n values(Initially Brownlie for movable bed, unknown for banks)

    Uniform Flow with Final ManningUniform Flow with Final Mannings n valuess n values(Initially Brownlie for movable bed, unknown for banks)(Initially Brownlie for movable bed, unknown for banks)

    N t l S l R hN t l S l R hN t l S l R h

  • 7/26/2019 Fluvial Geomorphology.pdf

    37/84

    3737

    Natural Supply ReachNatural Supply ReachNatural Supply Reach

    E i l t T id l Ch lE i l t T id l Ch lE i l t T id l Ch l

  • 7/26/2019 Fluvial Geomorphology.pdf

    38/84

    3838

    Equivalent Trapezoidal ChannelEquivalent Trapezoidal ChannelEquivalent Trapezoidal Channel

    Abnk Pbnkh

    0

    5

    10

    15

    20

    0 10 20 30 40 50 60 70 80

    Station(ft)

    E

    levation

    (ft)

    StaElevPoints Bankfull WaterSurface

    EquivalentChannel MovableBed

    0

    5

    10

    15

    20

    0 10 20 30 40 50 60 70 80

    Station(ft)

    Ele

    vation

    (ft)

    StaElevPoints Bankfull WaterSurface

    EquivalentChannel MovableBed

    Equivalent

    Trapezoidal ChannelEquivalent

    Trapezoidal Channel

    T id l Ch l S l R hT id l Ch l S l R hTrape oidal Channel S ppl Reach

  • 7/26/2019 Fluvial Geomorphology.pdf

    39/84

    3939

    Trapezoidal Channel Supply ReachTrapezoidal Channel Supply ReachTrapezoidal Channel Supply Reach

    St bl Ch l D i F tiStable Channel Design F nctionStable Channel Design Function

  • 7/26/2019 Fluvial Geomorphology.pdf

    40/84

    4040

    Stable Channel Design FunctionStable Channel Design FunctionStable Channel Design Function

    ComputeComputeCompute

  • 7/26/2019 Fluvial Geomorphology.pdf

    41/84

    4141

    ComputeComputeCompute

    Select Design Channel for b = 20 ftSelect Design Channel for b = 20 ftSelect Design Channel for b = 20 ft

  • 7/26/2019 Fluvial Geomorphology.pdf

    42/84

    4242

    Select Design Channel for b = 20 ftSelect Design Channel for b = 20 ftSelect Design Channel for b = 20 ft

    20 FT20 FT

    Stability Curve Width vs SlopeStability Curve Width vs SlopeStability Curve Width vs Slope

  • 7/26/2019 Fluvial Geomorphology.pdf

    43/84

    4343

    Stability Curve, Width vs. SlopeStability Curve, Width vs. SlopeStability Curve, Width vs. Slope

    181.42 ppm181.42 ppm

  • 7/26/2019 Fluvial Geomorphology.pdf

    44/84

    4444

    Gravel/Cobble Beds

    HEC-RAS Sediment

    Transport Capacity

    Function

    Gravel/Cobble BedsGravel/Cobble Beds

    HECHEC--RAS SedimentRAS Sediment

    Transport CapacityTransport Capacity

    FunctionFunction

  • 7/26/2019 Fluvial Geomorphology.pdf

    45/84

    4545

    HR Sediment Transport Capacity (STC)HR Sediment Transport Capacity (STC)HR Sediment Transport Capacity (STC)Grain size classes are input as grain size

    and percent finer.

    Computes STC for each size class, gsi

    Total STC is computed by the equationgs,total = pigsiwhere pi = fraction of size class i in the bed.

    Can compute the total STC for all sixSediment Transport Potential functions.

    Grain size classes are input as grain sizeGrain size classes are input as grain sizeand percent finer.and percent finer.

    Computes STC for each size class, gComputes STC for each size class, gsisi

    Total STC is computed by the equationTotal STC is computed by the equationggs,totals,total == ppiiggsisiwhere pwhere pii = fraction of size class i in the bed.= fraction of size class i in the bed.

    Can compute the total STC for all sixCan compute the total STC for all sixSediment Transport Potential functions.Sediment Transport Potential functions.

  • 7/26/2019 Fluvial Geomorphology.pdf

    46/84

    4646

    Gravel/Cobble ExampleGravel/Cobble ExampleGravel/Cobble Example

    The stream has the following bank-full

    conditions

    Water surface elevation = 11.7 feetDischarge = 3,100 cfs

    Slope = 0.0015.

    The stream has the following bank-full

    conditions

    Water surface elevation = 11.7 feetDischarge = 3,100 cfs

    Slope = 0.0015.

    12027.78

    0

    10

    20

    30

    0 20 40 60 80 100 120 140 160

    Station (ft)

    E

    levation(ft)

    Sta-Elev Bankfull Elevation Movable Bed

    12027.78

    0

    10

    20

    30

    0 20 40 60 80 100 120 140 160

    Station (ft)

    Elevation(ft)

    Sta-Elev Bankfull Elevation Movable Bed

    5252 9696

  • 7/26/2019 Fluvial Geomorphology.pdf

    47/84

    4747

    Pebble Count for Gravel/Cobble StreamPebble Count for Gravel/Cobble StreamPebble Count for Gravel/Cobble StreamINCHES PARTICLE MILLIMETER SIZE CLASS COUNT % CUM % Dtop(mm)

    Silt/Clay < 0.062 S/C 12 12 12

    Very Fine .062 - .125 S 7 7 19 0.125

    Fine .125 - .25 A 2 2 21 0.25

    Medium .25 - .50 N 2 2 23 0.5

    Coarse .50 - 1.0 D 4 4 27 1

    .04 - .08 Very Coarse 1.0 - 2 S 3 3 30 2.00

    .08 - .16 Very Fine 2 - 4 12 12 42 4.00

    .16 - .24 Fine 4 - 5.7 G 2 2 44 5.7

    .24 - .31 Fine 5.7 - 8 R 3 3 47 8.00

    .31 - .47 Medium 8 - 11.3 A 1 1 48 11.3

    .47 - .63 Medium 11.3 - 16 V 0 0 48 16.00

    .63 - .94 Coarse 16 - 22.6 E 2 2 50 22.6

    .94 - 1.26 Coarse 22.6 - 32 L 5 5 55 32.00

    1.26 - 1.9 Very Coarse 32 - 45 S 7 7 62 45.00

    1.9 - 2.5 Very Coarse 45 - 64 6 6 68 64.00

    2.5 - 3.8 Small 64 - 90 C - 6 6 74 90.00

    3.8 - 5.0 Small 90 - 128 O L 6 6 80 128

    5.0 - 7.6 Large 128 - 180 B E 6 6 86 180

    7.6 - 10 Large 180 - 256 B S 5 5 91 256

    10 - 15 Small 256 - 362 B D 1 1 92 362

    15 - 20 Small 362 - 512 O E 1 1 93 512

    20 - 40 Medium 512 - 1024 U R 0 0 93 1024

    40 - 160 Lrg to Very Lrg 1024 - 2048 L S 0 0 93 2048

    BEDROCK BDRK 7 7 100

    NOTENOTE

  • 7/26/2019 Fluvial Geomorphology.pdf

    48/84

    4848

    Log-probability plot of Bed MaterialLogLog--probability plot of Bed Materialprobability plot of Bed Material

    Sand Gravel Cobble

    Make New HEC-RAS Model with oneMake New HECMake New HEC--RAS Model with oneRAS Model with one

  • 7/26/2019 Fluvial Geomorphology.pdf

    49/84

    4949

    cross section and no dischargecross section and no dischargecross section and no discharge

    Uniform Flow Bed uses Limerinos banksUniform FlowUniform Flow Bed uses Limerinos banksBed uses Limerinos banks

  • 7/26/2019 Fluvial Geomorphology.pdf

    50/84

    5050

    Uniform Flow Bed uses Limerinos, banks

    use Manning (T&E gives nbank = 0.077)

    Uniform FlowUniform Flow Bed uses Limerinos, banksBed uses Limerinos, banks

    use Manning (T&E gives nuse Manning (T&E gives nbankbank = 0.077)= 0.077)

    Uniform Flow Bed uses Mannings BanksUniform FlowUniform Flow Bed uses Mannings BanksBed uses Mannings, Banks

  • 7/26/2019 Fluvial Geomorphology.pdf

    51/84

    5151

    Uniform Flow Bed uses Mannings, Banks

    use n = 0.077 (T&E gives nbed = 0.0363)

    Uniform FlowUniform Flow Bed uses Mannings, BanksBed uses Mannings, Banks

    use n = 0.077 (T&E gives nuse n = 0.077 (T&E gives nbedbed = 0.0363)= 0.0363)

    Create and Run Natural Supply ReachCreate and Run Natural Supply ReachCreate and Run Natural Supply Reach

  • 7/26/2019 Fluvial Geomorphology.pdf

    52/84

    5252

    pp ypp ypp y

    Sediment Transport Capacity FunctionSediment Transport Capacity FunctionSediment Transport Capacity Function

  • 7/26/2019 Fluvial Geomorphology.pdf

    53/84

    5353

    Sediment Transport Capacity FunctionInput Grain Sizes (Fake size for banks)

    Sediment Transport Capacity FunctionSediment Transport Capacity FunctionInput Grain Sizes (Fake size for banks)Input Grain Sizes (Fake size for banks)

    Diam, mm % Finer Diam, mm % Finer Diam, mm % Finer

    2000 19 0.125 19 2000 19

    2000 21 0.25 21 2000 21

    2000 23 0.5 23 2000 23

    2000 27 1 27 2000 27

    2000 30 2 30 2000 30

    2000 42 4 42 2000 42

    2000 44 5.7 44 2000 44

    2000 47 8 47 2000 47

    2000 48 11.3 48 2000 48

    2000 48 16 48 2000 48

    2000 50 22.6 50 2000 502000 55 32 55 2000 55

    2000 62 45 62 2000 62

    2000 68 64 68 2000 68

    2000 74 90 74 2000 74

    2000 80 128 80 2000 80

    2000 86 180 86 2000 86

    2000 91 256 91 2000 91

    2000 92 362 92 2000 92

    2000 93 512 93 2000 93

    2000 93 1024 93 2000 93

    2000 93 2048 93 2000 93

    ROBLOB Main

    Compute Sediment Rating Curve PlotCompute Sediment Rating Curve PlotCompute Sediment Rating Curve Plot

  • 7/26/2019 Fluvial Geomorphology.pdf

    54/84

    5454

    Compute, Sediment Rating Curve Plot,

    Generate Report

    Compute, Sediment Rating Curve Plot,Compute, Sediment Rating Curve Plot,

    Generate ReportGenerate Report

  • 7/26/2019 Fluvial Geomorphology.pdf

    55/84

    Meyer-Peter Mueller Function ResultsMeyerMeyer--Peter Mueller Function ResultsPeter Mueller Function Results

  • 7/26/2019 Fluvial Geomorphology.pdf

    56/84

    5656

    1010

    77

    Design 1 (b = 35 ft m = 3:1 hor: vert)Design 1 (b = 35 ft m = 3:1 hor: vert)Design 1 (b = 35 ft m = 3:1 hor: vert)

  • 7/26/2019 Fluvial Geomorphology.pdf

    57/84

    5757

    Design 1 (b = 35 ft, m = 3:1 hor: vert)Design 1 (b = 35 ft, m = 3:1 hor: vert)Design 1 (b = 35 ft, m = 3:1 hor: vert)

    Assume slope

    Create 3 cross section model with

    trapezoidal xsecs with same ns and Q assupply reach

    Run steady flow model

    Run Sediment Transport Capacity function

    See if STC equals 1083 tons/day if not back

    to the top with a new slope

    Assume slopeAssume slope

    Create 3 cross section model withCreate 3 cross section model with

    trapezoidal xsecs with same ntrapezoidal xsecs with same ns and Q ass and Q assupply reachsupply reach

    Run steady flow modelRun steady flow model

    Run Sediment Transport Capacity functionRun Sediment Transport Capacity function

    See if STC equals 1083 tons/daySee if STC equals 1083 tons/day if not backif not back

    to the top with a new slopeto the top with a new slope

    Design 1 (b = 35 ft, m = 3:1 hor: vert)Design 1 (b = 35 ft, m = 3:1 hor: vert)Design 1 (b = 35 ft, m = 3:1 hor: vert)

  • 7/26/2019 Fluvial Geomorphology.pdf

    58/84

    5858

    S = 0.003 S = 0.0017

    b = 35 Natural Design b = 35 Natural Design

    Function Function

    A-W 836000 410900... NA A-W 836000 113600... NAE-H 8217 26640 0.31 E-H 8217 9883 0.83

    Laur 645200 212400... NA Laur 645200 750300 0.86

    MPM 1083 2427 0.45 MPM 1083 1151 0.94

    Toff 680.4 627 1.09 Toff 680.4 586.7 1.16

    Yang 27290 88360 0.31 Yang 27290 32300 0.84

    S = 0.0016 S = 0.00162

    b = 35 Natural Design b = 35 Natural Design

    Function Function

    A-W 836000 992100 0.84 A-W 836000 102100... NA

    E-H 8217 8908 0.92 E-H 8217 9105 0.90

    Laur 645200 673200 0.96 Laur 645200 688800 0.94

    MPM 1083 1063 1.02 MPM 1083 1081 1.00

    Toff 680.4 582.9 1.17 Toff 680.4 583.7 1.17

    Yang 27290 29000 0.94 Yang 27290 29670 0.92

    Nat/Des

    Nat/Destons/day

    Nat/Des

    tons/day

    tons/day

    Nat/Destons/day

    S = 0.003 S = 0.0017

    b = 35 Natural Design b = 35 Natural Design

    Function Function

    A-W 836000 410900... NA A-W 836000 113600... NA

    E-H 8217 26640 0.31 E-H 8217 9883 0.83

    Laur 645200 212400... NA Laur 645200 750300 0.86

    MPM 1083 2427 0.45 MPM 1083 1151 0.94

    Toff 680.4 627 1.09 Toff 680.4 586.7 1.16

    Yang 27290 88360 0.31 Yang 27290 32300 0.84

    S = 0.0016 S = 0.00162

    b = 35 Natural Design b = 35 Natural Design

    Function Function

    A-W 836000 992100 0.84 A-W 836000 102100... NAE-H 8217 8908 0.92 E-H 8217 9105 0.90

    Laur 645200 673200 0.96 Laur 645200 688800 0.94

    MPM 1083 1063 1.02 MPM 1083 1081 1.00

    Toff 680.4 582.9 1.17 Toff 680.4 583.7 1.17

    Yang 27290 29000 0.94 Yang 27290 29670 0.92

    Nat/Des

    Nat/Destons/day

    Nat/Des

    tons/day

    tons/day

    Nat/Destons/day

    T & E gives S = 0.00162T & E gives S = 0.00162

    Final DesignFinal DesignFinal Design

  • 7/26/2019 Fluvial Geomorphology.pdf

    59/84

    5959

    Design 2 - Select slope and sideDesign 2Design 2 -- Select slope and sideSelect slope and side

  • 7/26/2019 Fluvial Geomorphology.pdf

    60/84

    6060

    g

    slopes, find bslopes, find bslopes, find b

    b = 15

    bnk ht = 15.62 S = 0.0018 m = 2.5 Function All Grains

    RS 0 RS 100 RS 200 A-W 192600...

    Station Elevation Station Elevation Station Elevation E-H 12280-46.550 15.620 -46.550 15.800 -46.550 15.980 Laur 901500

    -7.500 0.000 -7.500 0.180 -7.500 0.360 MPM 1091

    7.500 0.000 7.500 0.180 7.500 0.360 Toff 438.7

    46.550 15.620 46.550 15.800 46.550 15.980 Yang 37320

    STC in Tons/Dayb = 15

    bnk ht = 15.62 S = 0.0018 m = 2.5 Function All Grains

    RS 0 RS 100 RS 200 A-W 192600...

    Station Elevation Station Elevation Station Elevation E-H 12280-46.550 15.620 -46.550 15.800 -46.550 15.980 Laur 901500

    -7.500 0.000 -7.500 0.180 -7.500 0.360 MPM 1091

    7.500 0.000 7.500 0.180 7.500 0.360 Toff 438.7

    46.550 15.620 46.550 15.800 46.550 15.980 Yang 37320

    STC in Tons/Day

    S = 0.0018, m = 2.5:1 hor: vertS = 0.0018, m = 2.5:1 hor: vertS = 0.0018, m = 2.5:1 hor: vert

    S = 0.0018, m = 2.5:1 hor: vertS = 0.0018, m = 2.5:1 hor: vertS = 0.0018, m = 2.5:1 hor: vert

  • 7/26/2019 Fluvial Geomorphology.pdf

    61/84

    6161

    S 0.0018, m 2.5:1 hor: vertS 0.0018, m 2.5:1 hor: vertS 0 00 8, 5 o e t

    Design Channel, b = 15', hor:vert = 2.5:1, S = 0.0018

    0

    4

    8

    12

    16

    -60 -40 -20 0 20 40 60

    Station (ft)

    Elevation

    (ft)

    Design Channel Bankfull Elevation Movable Bed

    Design Channel, b = 15', hor:vert = 2.5:1, S = 0.0018

    0

    4

    8

    12

    16

    -60 -40 -20 0 20 40 60

    Station (ft)

    Elevation

    (ft)

    Design Channel Bankfull Elevation Movable Bed

    b = 15 ft, bank ht = 15.62 ftb = 15 ft, bank ht = 15.62 ft

    Design 3 - S = 0.0013, m = 2.5:1 hor: vertDesign 3Design 3 -- S = 0.0013, m = 2.5:1 hor: vertS = 0.0013, m = 2.5:1 hor: vert

  • 7/26/2019 Fluvial Geomorphology.pdf

    62/84

    6262

    g ,gg ,

    0

    5

    10

    -60 -40 -20 0 20 40 60

    Station (ft)

    Elevation

    (ft)

    Design Channel Bankfull Elevation Movable Bed

    0

    5

    10

    -60 -40 -20 0 20 40 60

    Station (ft)Elevation

    (ft)

    Design Channel Bankfull Elevation Movable Bed

    b = 76 ft, bank ht = 8.73 ftb = 76 ft, bank ht = 8.73 ft

    4 b = 76.0 1082bnk ht = 8.73 S = 0.0013 m = 2.5 Tons/day

    RS 0 RS 100 RS 200 Function All Grains

    Station Elevation Station Elevation Station Elevation A-W 388200

    -59.825 8.730 -59.825 8.860 -59.825 8.990 E-H 4981

    -38 0.000 -38 0.130 -38 0.260 Laur 545400

    38 0.000 38 0.130 38 0.260 MPM 108259.825 8.730 59.825 8.860 59.825 8.990 Toff 1078

    Yang 19240

    Final Design 2MPM Gs (Tons/day) =4 b = 76.0 1082

    bnk ht = 8.73 S = 0.0013 m = 2.5 Tons/day

    RS 0 RS 100 RS 200 Function All Grains

    Station Elevation Station Elevation Station Elevation A-W 388200

    -59.825 8.730 -59.825 8.860 -59.825 8.990 E-H 4981

    -38 0.000 -38 0.130 -38 0.260 Laur 545400

    38 0.000 38 0.130 38 0.260 MPM 1082

    59.825 8.730 59.825 8.860 59.825 8.990 Toff 1078

    Yang 19240

    Final Design 2MPM Gs (Tons/day) = Final Design 3

    Sidewall Correction MethodSidewall Correction MethodSidewall Correction Method

  • 7/26/2019 Fluvial Geomorphology.pdf

    63/84

    6363

    bd

    yd

    md

    1

    md

    1 1

    md

    1

    md

    nwnw

    nb

    Wd

    } 4 /32 /3 1/ 2 2

    2 4 /3

    3/ 4 3/ 43/ 42 4 /3 2 2

    2 4 /3 2 3/ 2

    1 1'

    1 1 1

    square

    co

    AMetric version of Manning s Equation V R S V S

    n n P

    Einstein assumed V and S are constant in bank area and sidewall area

    V A V A A V

    S n P S n P n P S

    = =

    = = =

    ( ) ( ) ( )

    3/ 2 3/ 2 3/ 2

    3/ 2 3/ 2 3/ 2 3/ 2 3/ 2 3/ 2

    2 /3 3/ 2 3/ 23/ 2 3/ 2

    3/ 2 3/ 2

    1

    nstant

    Constantw b

    w b

    w b

    w bw b w b w w b b

    w w b bw w b b w b

    P PPn n n

    A A A

    P PPA A A n n n n P n P n P

    n P n Pn n P n P also A A and A A

    P n P n P

    = = =

    = + = + = +

    = + = =

    64748

    Aw/2Aw/2 AbAbAw/2Aw/2

    Sidewall ExampleSidewall ExampleSidewall Example

    S 0 0002

  • 7/26/2019 Fluvial Geomorphology.pdf

    64/84

    6464

    50

    5

    n = 0.025

    n = 0.045n = 0.045

    12

    12

    S = 0.0002

    nw = 0.040 nw = 0.040nb = 0.025

    ( ) ( )

    2 2

    2 2 2

    2 /3 2 /3

    3/ 2 3/ 2 3/ 2 3/ 2

    50 ; 2 5 10 22.4 72.4

    (5)(10)50*5 250 ; 2 50 300

    2

    1 1(0.040) 22.4 (0.025) 50

    72.4

    0.0300

    1.49 (300

    0.0300

    b w b w

    rect tria rect tria

    w w b b

    P ft P ft P P P ft

    A ft A ft A A A ft

    n n P n PP

    n

    Q

    = = + = = + =

    = = = = = + =

    = + = +

    =

    =

    ( ) ( )

    5/33

    2/3

    3/ 2 3/ 22 2

    3/ 2 3/ 2

    2 2

    )0.0002 543 /

    (72.4)(0.040) (0.025)22.4 50

    300 143 300 157(0.030) 72.4 (0.030) 72.4

    50 250

    w b

    w b

    ft s

    A ft and A ft

    Geometric values A ft and A ft

    =

    = = = =

    = =

    ARR Analytical MethodARR Analytical MethodARR Analytical Method

  • 7/26/2019 Fluvial Geomorphology.pdf

    65/84

    6565

    ( )

    ( )( )

    5/3

    2/3

    3/ 250

    3/2

    50

    50

    50

    1.49. 4 2

    8 0.047 . 4 6

    0.047 1. 4 8

    0.047 1

    , , , , 2.65, , .

    dd d

    d d

    s

    m sm

    m d d m

    d d s

    d d d m d s m m

    AManning for Design Channel Q S ARR Eq

    n P

    bMPM B yS d ARR Eq

    y S G dB B b b ARR Eq

    y S G d

    Given Q m n S S G d b and y

    =

    =

    = =

    = =

    . 4 2 4 8

    , .

    d dUse iteration to solve Eqs and for b and y by iteration

    Subscripts d and m denote design channel and match reach channels respectively

    bd

    yd

    md

    1

    md

    1 1

    md

    1

    md

    nwnw

    nb

    Wd

    nd = Manningscomposite n

    ARR vs HEC-RASComposite n 0 061 from HEC RAS Supply Reach

    ARR vs HECARR vs HEC--RASRASComposite nComposite n 0 061 from HEC0 061 from HEC RAS Supply ReachRAS Supply Reach

  • 7/26/2019 Fluvial Geomorphology.pdf

    66/84

    6666

    Composite n 0.061 from HEC-RAS Supply ReachComposite nComposite n 0.061 from HEC0.061 from HEC--RAS Supply ReachRAS Supply ReachARR solution for Design 1 ( HR solution bd= 35 ft) dm(mm)

    md = 3 Sd = 0.001622 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    10.96 42.9 829.9 112.2 108.6 3100 0.000

    ARR solution for Design 2 ( HR solution bd= 15 ft) dm(mm)

    md = 2.5 Sd = 0.0018 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    13.38 22.8 752.1 94.8 89.7 3100 0.000

    ARR solution for Design 3 ( HR solution bd = 76 ft) dm (mm)

    md = 2.5 Sd = 0.0013 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 3897.35 797.350

    ARR solution for Design 1 ( HR solution bd= 35 ft) dm(mm)

    md = 3 Sd = 0.001622 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    10.96 42.9 829.9 112.2 108.6 3100 0.000

    ARR solution for Design 2 ( HR solution bd= 15 ft) dm(mm)

    md = 2.5 Sd = 0.0018 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    13.38 22.8 752.1 94.8 89.7 3100 0.000

    ARR solution for Design 3 ( HR solution bd = 76 ft) dm (mm)

    md = 2.5 Sd = 0.0013 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 3897.35 797.350

    ARR solution for Design 1 ( HR solution bd= 35 ft) dm(mm)

    md = 3 Sd = 0.001622 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    10.96 42.9 829.9 112.2 108.6 3100 0.000

    ARR solution for Design 2 ( HR solution bd= 15 ft) dm(mm)

    md = 2.5 Sd = 0.0018 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    13.38 22.8 752.1 94.8 89.7 3100 0.000

    ARR solution for Design 3 ( HR solution bd = 76 ft) dm(mm)

    md = 2.5 Sd = 0.0013 nd = 0.061 22.6yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 3897.35 797.350

    ARR solution for Design 1 ( HR solution bd= 35 ft) dm(mm)

    md = 3 Sd = 0.001622 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    10.96 42.9 829.9 112.2 108.6 3100 0.000

    ARR solution for Design 2 ( HR solution bd= 15 ft) dm(mm)

    md = 2.5 Sd = 0.0018 nd = 0.061 22.6

    yd bd Ad Pd Wb Qb Q

    13.38 22.8 752.1 94.8 89.7 3100 0.000

    ARR solution for Design 3 ( HR solution bd = 76 ft) dm(mm)

    md = 2.5 Sd = 0.0013 nd = 0.061 22.6yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 3897.35 797.350

    bHR = 35 ft

    bARR= 42.9 ftbHR/bARR= 0.82

    bHR = 35 ft

    bARR= 42.9 ftbHR/bARR= 0.82

    bHR = 15 ft

    bARR= 22.8 ftbHR/bARR= 0.66

    bHR = 15 ft

    bARR= 22.8 ftbHR/bARR= 0.66

    ARR did not converge

    bHR = 76 ft

    bARR= 58.8 ftbHR/bARR= 1.29

    ARR did not convergebHR = 76 ft

    bARR= 58.8 ftbHR/bARR= 1.29

    ARR vs HEC-RASComposite n values from HR Design Reaches

    ARR vs HECARR vs HEC--RASRASComposite n values from HR Design ReachesComposite n values from HR Design Reaches

  • 7/26/2019 Fluvial Geomorphology.pdf

    67/84

    6767

    Composite n values from HR Design ReachesComposite n values from HR Design ReachesComposite n values from HR Design Reaches(b) ARR solution for Design 1 ( HR solution b

    d

    = 35 ft)

    md = 3 Sd = 0.00162 nd = 0.066 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    12.35 33.2 867.7 111.3 107.3 3100 0.000

    (c) ARR solution for Design 2 ( HR solution bd= 15 ft)

    md = 2.5 Sd = 0.0018 nd = 0.072 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    15.19 17.8 847.3 99.6 93.8 3100 0.000

    (d) ARR solution for Design 3 ( HR solution bd= 76 ft)

    md = 2.5 Sd = 0.0013 nd = 0.054 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 4402.562 1302.562

    (b) ARR solution for Design 1 ( HR solution bd= 35 ft)md = 3 Sd = 0.00162 nd = 0.066 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    12.35 33.2 867.7 111.3 107.3 3100 0.000

    (c) ARR solution for Design 2 ( HR solution bd= 15 ft)

    md = 2.5 Sd = 0.0018 nd = 0.072 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    15.19 17.8 847.3 99.6 93.8 3100 0.000

    (d) ARR solution for Design 3 ( HR solution bd= 76 ft)

    md = 2.5 Sd = 0.0013 nd = 0.054 dm (mm)= 22.6

    yd bd Ad Pd Wb Qb Q

    11.91 58.8 1055.6 123.0 118.4 4402.562 1302.562

    n = 0.066

    bHR = 35 ft

    bARR= 33.2 ft

    bHR/bARR= 1.05

    n = 0.066

    bHR = 35 ft

    bARR= 33.2 ft

    bHR/bARR= 1.05

    n = 0.072

    bHR = 15 ft

    bARR= 17.8 ftbHR/bARR= 0.84

    n = 0.072

    bHR = 15 ft

    bARR= 17.8 ftbHR/bARR= 0.84

    ARR did not converge

    n = 0.054bHR = 76 ft

    bARR= 58.8 ftbHR/bARR= 1.29

    ARR did not converge

    n = 0.054bHR = 76 ft

    bARR= 58.8 ftbHR/bARR= 1.29

    ARRs Simplified MPM EquationARRARRs Simplified MPM Equations Simplified MPM Equation

    RR simplified MPM equation

  • 7/26/2019 Fluvial Geomorphology.pdf

    68/84

    6868

    ( ) 3/ 2

    3/ 2

    '

    '

    ( )

    8( ) 0.047

    b s m

    b

    b

    b

    b

    eyer Peter Mueller MPM

    bB RKR R S d

    nRKR Nikuradse roughness ratio

    n

    n Manning coefficient for grain size

    n total Manning coefficient

    =

    = =

    =

    =

    }

    ( )}

    50

    3/ 21

    3/ 28 ( ) 0.047

    dy

    b s m

    RR simplified MPM equation

    bB RKR R S d

    =

    64748

  • 7/26/2019 Fluvial Geomorphology.pdf

    69/84

    Analysis of Bed Grain SizeAnalysis of Bed Grain SizeAnalysis of Bed Grain Size

  • 7/26/2019 Fluvial Geomorphology.pdf

    70/84

    7070

    DistributionDistributionDistribution

    Sieve AnalysisVisual-Accumulation Tube

    Pebble Count

    Sieve AnalysisSieve AnalysisVisualVisual--Accumulation TubeAccumulation Tube

    Pebble CountPebble Count

    Log-normal DistributionLogLog--normal Distributionnormal Distribution

  • 7/26/2019 Fluvial Geomorphology.pdf

    71/84

    7171

    84.1

    log 15.9

    50

    loglog

    log84.1 84

    15.9 16

    log

    log log1 1(log ) exp

    22

    10 10

    (log ) (log ) (log ) /100

    d

    dd

    d

    d

    g

    d

    Probability Density Function PDF

    d df d

    Cumulative Distribution Function CDF

    d d

    d d

    F d f d d d P

    Standa

    =

    = = =

    = =

    84.1

    log 15.9

    84.1 84.1log 84.1 15.9

    15.9 15.9

    log84.1 84

    15.9 16

    1 1(log log ) log log

    2 2

    10 10d

    d

    d

    d

    g

    rdDeviation

    d dd d

    d d

    Geometric standard deveiation

    d d

    d d

    = = =

    = = =

    Standardized Random VariableMean = 0, standard deviation =1

    Standardized Random VariableStandardized Random VariableMean = 0, standard deviation =1Mean = 0, standard deviation =1

  • 7/26/2019 Fluvial Geomorphology.pdf

    72/84

    7272

    Mean 0, standard deviation 1Mean 0, standard deviation 1,

    2

    50

    log

    log log 1( ) exp

    22

    ( ) ( ) ( ) 1 ( )

    d

    z

    d d zz PDF f z

    CDF F z f z dz where F z F z

    = =

    = =

    F(z) for Standard Normal Random Variable zF(z) for Standard Normal Random Variable z

    z 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

    0 0.5000 0.5040 0.5080 0.5120 0.5160 0.5199 0.5239 0.5279 0.5319 0.53590.1 0.5398 0.5438 0.5478 0.5517 0.5557 0.5596 0.5636 0.5675 0.5714 0.5753

    0.2 0.5793 0.5832 0.5871 0.5910 0.5948 0.5987 0.6026 0.6064 0.6103 0.6141

    0.3 0.6179 0.6217 0.6255 0.6293 0.6331 0.6368 0.6406 0.6443 0.6480 0.6517

    0.4 0.6554 0.6591 0.6628 0.6664 0.6700 0.6736 0.6772 0.6808 0.6844 0.6879

    0.5 0.6915 0.6950 0.6985 0.7019 0.7054 0.7088 0.7123 0.7157 0.7190 0.7224

    0.6 0.7257 0.7291 0.7324 0.7357 0.7389 0.7422 0.7454 0.7486 0.7517 0.7549

    0.7 0.7580 0.7611 0.7642 0.7673 0.7703 0.7734 0.7764 0.7793 0.7823 0.7852

    0.8 0.7881 0.7910 0.7939 0.7967 0.7995 0.8023 0.8051 0.8078 0.8106 0.81330.9 0.8159 0.8186 0.8212 0.8238 0.8264 0.8289 0.8315 0.8340 0.8365 0.8389

    1 0.8413 0.8438 0.8461 0.8485 0.8508 0.8531 0.8554 0.8577 0.8599 0.8621

    1.1 0.8643 0.8665 0.8686 0.8708 0.8729 0.8749 0.8770 0.8790 0.8810 0.8830

    1.2 0.8849 0.8869 0.8888 0.8906 0.8925 0.8943 0.8962 0.8980 0.8997 0.9015

    1.3 0.9032 0.9049 0.9066 0.9082 0.9099 0.9115 0.9131 0.9147 0.9162 0.9177

    1.4 0.9192 0.9207 0.9222 0.9236 0.9251 0.9265 0.9279 0.9292 0.9306 0.9319

    z 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

    0 0.5000 0.5040 0.5080 0.5120 0.5160 0.5199 0.5239 0.5279 0.5319 0.5359

    0.1 0.5398 0.5438 0.5478 0.5517 0.5557 0.5596 0.5636 0.5675 0.5714 0.5753

    0.2 0.5793 0.5832 0.5871 0.5910 0.5948 0.5987 0.6026 0.6064 0.6103 0.6141

    0.3 0.6179 0.6217 0.6255 0.6293 0.6331 0.6368 0.6406 0.6443 0.6480 0.6517

    0.4 0.6554 0.6591 0.6628 0.6664 0.6700 0.6736 0.6772 0.6808 0.6844 0.6879

    0.5 0.6915 0.6950 0.6985 0.7019 0.7054 0.7088 0.7123 0.7157 0.7190 0.7224

    0.6 0.7257 0.7291 0.7324 0.7357 0.7389 0.7422 0.7454 0.7486 0.7517 0.7549

    0.7 0.7580 0.7611 0.7642 0.7673 0.7703 0.7734 0.7764 0.7793 0.7823 0.7852

    0.8 0.7881 0.7910 0.7939 0.7967 0.7995 0.8023 0.8051 0.8078 0.8106 0.81330.9 0.8159 0.8186 0.8212 0.8238 0.8264 0.8289 0.8315 0.8340 0.8365 0.8389

    1 0.8413 0.8438 0.8461 0.8485 0.8508 0.8531 0.8554 0.8577 0.8599 0.8621

    1.1 0.8643 0.8665 0.8686 0.8708 0.8729 0.8749 0.8770 0.8790 0.8810 0.8830

    1.2 0.8849 0.8869 0.8888 0.8906 0.8925 0.8943 0.8962 0.8980 0.8997 0.9015

    1.3 0.9032 0.9049 0.9066 0.9082 0.9099 0.9115 0.9131 0.9147 0.9162 0.9177

    1.4 0.9192 0.9207 0.9222 0.9236 0.9251 0.9265 0.9279 0.9292 0.9306 0.9319

    Example - Sand Bed MaterialExampleExample -- Sand Bed MaterialSand Bed Material

  • 7/26/2019 Fluvial Geomorphology.pdf

    73/84

    7373

    Log-Probability Plot of Sand Bed DataLogLog--Probability Plot of Sand Bed DataProbability Plot of Sand Bed Data

  • 7/26/2019 Fluvial Geomorphology.pdf

    74/84

    7474

    d(mm)

    Cumulative Distribution Function Expressed as a probability (%)

    d84=0.363 mm

    d50=0.232 mm

    d16=0.158 mm

    ( ) ( )log 50

    84.1log

    15.9

    0.181

    0.386 log 0.386 0.181 log 0.232 .565

    65

    0.363log log 0.181

    0.158

    10 1.52

    10 10 10 0.272d

    d

    g

    d

    d

    d

    d mm

    + +

    = = =

    = =

    = = = =

    Log Probability Plot using NORMSINVLog Probability Plot using NORMSINVLog Probability Plot using NORMSINV

  • 7/26/2019 Fluvial Geomorphology.pdf

    75/84

    7575

    Function in EXCELFunction in EXCELFunction in EXCEL

    -1.2

    -1.0

    -0.8

    -0.6

    -0.4

    -0.2

    -4 -3 -2 -1 0 1 2 3

    log10

    (d)

    d15.9

    NORMSINV(P/100)

    d50 d84.1

    log(d84)log(d84))

    log(d50)log(d50))

    log(d16)log(d16))

    NORMSINV and NORMSDIST

    EXCEL Functions

    NORMSINV and NORMSDISTNORMSINV and NORMSDIST

    EXCEL FunctionsEXCEL Functions

  • 7/26/2019 Fluvial Geomorphology.pdf

    76/84

    7676

    d50= 0.48 mm log10(d50)= -0.3188

    g= 1.28 mm log10(g)= 0.1072

    P (% finer) F(z) z=NORMSINV(F) di (mm) F(z)=NORMSDIST(z)

    1 2 3 4 5 6

    20 0.2 -0.8416 d20= 0.390 0.2

    40 0.4 -0.2533 d40= 0.451 0.4

    60 0.6 0.2533 d60= 0.511 0.6

    80 0.8 0.8416 d80= 0.591 0.8

    99.99 0.9999 3.7190 d99.99= 1.202 0.9999

    50 0.5 0.0000 d50= 0.480 0.5

    di (mm) z F(z)=NORMSDIST(z) P (% finer)

    1 2 3 4

    0.41 -0.6385 0.2616 26.2

    0.63 1.1016 0.8647 86.5

    50

    50

    ( ) ( )

    ( ) ( )

    ( )

    10 i g

    ii

    g

    log d z log

    i

    log d log d z

    log

    d

    +

    =

    =

    50( ) ( )

    ( )i

    i

    g

    log d log d z

    log

    =

    d50= 0.48 mm log10(d50)= -0.3188

    g= 1.28 mm log10(g)= 0.1072

    P (% finer) F(z) z=NORMSINV(F) di (mm) F(z)=NORMSDIST(z)

    1 2 3 4 5 6

    20 0.2 -0.8416 d20= 0.390 0.2

    40 0.4 -0.2533 d40= 0.451 0.4

    60 0.6 0.2533 d60= 0.511 0.6

    80 0.8 0.8416 d80= 0.591 0.8

    99.99 0.9999 3.7190 d99.99= 1.202 0.999950 0.5 0.0000 d50= 0.480 0.5

    di (mm) z F(z)=NORMSDIST(z) P (% finer)

    1 2 3 4

    0.41 -0.6385 0.2616 26.2

    0.63 1.1016 0.8647 86.5

    50

    50

    ( ) ( )

    ( ) ( )

    ( )

    10 i g

    ii

    g

    log d z log

    i

    log d log d z

    log

    d

    +

    =

    =

    50( ) ( )( )

    ii

    g

    log d log d zlog

    =

    Geometric Standard DeviationGeometric Standard DeviationGeometric Standard Deviation

  • 7/26/2019 Fluvial Geomorphology.pdf

    77/84

    7777

    ( ) ( )

    ( ) ( ) ( ) ( )( )

    ( ) ( )

    ( )

    84 50 50 16

    84 50 50 16 84 50 16 50

    84 16 84 16 84 16

    84 16

    84 50 84 50

    2log log log log log

    2log log / log / log /

    12log log / log log / log /2

    /

    log log log /

    log

    top top

    d d d d

    d d d d d d d d

    d d d d d d

    d d

    Alternative Method in HEC RAS Manuald d d d

    = +

    = + =

    = = =

    =

    = =

    ( )

    ( )

    50 16 50 16

    84 50

    50 16

    log log /

    0.5 0.5

    bot bot

    ave top bot

    d d d d

    d d

    d d

    = =

    = = + = +

    Geometric Standard Deviation when

    P for smallest sample d is greater than 0.16

    Geometric Standard Deviation whenGeometric Standard Deviation when

    PP for smallest sample d is greater than 0.16for smallest sample d is greater than 0.16

  • 7/26/2019 Fluvial Geomorphology.pdf

    78/84

    7878

    Pifor smallest sample d is greater than 0.16PP

    iifor smallest sample d is greater than 0.16for smallest sample d is greater than 0.16

    ( )

    ( )

    1

    1 1

    1

    1

    84

    84 1

    (1 )84 84

    1

    (1 )

    84

    (1 )log log log

    loglog loglog log

    (1 ) (1 )

    P

    zP P

    P

    z

    P

    z d d

    d

    d d d d

    z z d

    dd

    =

    = = =

    =

    Let Pi = the lowest percent finer from the pebble

    count analysis and let zi = the standardized

    normal variable that gives F(z) = Pi/100.

    Let Pi = the lowest percent finer from the pebble

    count analysis and let zi = the standardized

    normal variable that gives F(z) = Pi/100.

    Example for Smallest d > d16Example for Smallest d > dExample for Smallest d > d1616

  • 7/26/2019 Fluvial Geomorphology.pdf

    79/84

    7979

    ( )

    1

    84 32

    1

    11 1

    (1 )(1 0.469 ) 1.469

    84

    8450 84

    8450

    8 2

    32 ( ) 0.32 ( ) 1 ( ) 1 0.32 0.68

    0.469 0.469

    5.7 5.72.04

    2 2

    log log log 2.04 log2.04

    2.

    z

    P

    Given d mm and d mm

    P F z F z F z

    z z

    d

    d

    dd d

    dd

    = =

    = = = = =

    = =

    = = = =

    = =

    = 5.7 2.7904 2.04

    mm = =

    Pebble Count for Gravel/Cobble StreamPebble Count for Gravel/Cobble StreamPebble Count for Gravel/Cobble Stream

  • 7/26/2019 Fluvial Geomorphology.pdf

    80/84

    8080

    Sand Gravel Cobble

    Theoretical Justification for Pebble

    Count

    Theoretical Justification for PebbleTheoretical Justification for Pebble

    CountCount

  • 7/26/2019 Fluvial Geomorphology.pdf

    81/84

    8181

    0

    , , ,

    / ; ; ( )

    (1 )

    /

    (1 )

    L

    pores total pores pores pores

    s

    i

    i i s

    i s i i ii

    s total s s total s total total

    i

    porosity V V A nA V A x dx

    A n A area of A occupied by soil

    A area of A occupied by particles of a specified size range

    f A A

    W V V V p

    W V V n V

    p

    = = =

    = =

    =

    =

    = = = =

    ( ) [ ]( )

    [ ]( )

    0 0 0 0

    0 0

    (1 )

    (1 ) (1 ) (1 ) (1 )

    (1 ) (1 )(1 )

    (1 ) (1 ) (1 )

    L L L L

    i i i s i

    total

    L L

    i i

    i

    i

    i i

    A dx A dx f A dx p n A dx

    n V n AL n AL n AL

    f n A dx f n Adxf n AL

    p n AL n AL n AL

    p f

    = = = =

    = = =

    =

    L

    SOIL PARTICLES

    PORES

    A

    Actual Pebble Count Shielding, settling, etc.Actual Pebble Count Shielding, settling, etc.

    Mixed Sand and Gravel BedsWatershed Institute, Inc. Pebble Count Data

    Mixed Sand and Gravel BedsMixed Sand and Gravel BedsWatershed Institute, Inc. Pebble Count DataWatershed Institute, Inc. Pebble Count Data

  • 7/26/2019 Fluvial Geomorphology.pdf

    82/84

    8282

    MT043442RR01

    D16 D50 D84

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    2.5

    3

    -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5

    normsinv(P/100)

    log10(D)

    Pebble Count Data D16 D50 D84 Extrapolated

    D (mm)

    D16 0.0763

    D50 0.344

    D84 14.8

    d (mm)

    d16 0.0763

    d50 0.344

    d84 14.8

    d16 d50 d84MT043442RR01

    D16 D50 D84

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    2.5

    3

    -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5

    normsinv(P/100)

    log10(D)

    Pebble Count Data D16 D50 D84 Extrapolated

    D (mm)

    D16 0.0763D50 0.344

    D84 14.8

    d (mm)

    d16 0.0763d50 0.344

    d84 14.8

    d16 d50 d84

    SN321115RR

    D16 D50 D84

    -3

    -2

    -1

    0

    1

    2

    3

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    normsinv(P/100)

    log10(D)

    Pebble Count Data D16 D50 D84 Extrapolated

    D (mm)

    D16 0.00224

    D50 0.500D84 20.6

    d (mm)

    d16 0.00224

    d50 0.5d84 20.6

    d16 d50 d84SN321115RR

    D16 D50 D84

    -3

    -2

    -1

    0

    1

    2

    3

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    normsinv(P/100)

    log10(D)

    Pebble Count Data D16 D50 D84 Extrapolated

    D (mm)

    D16 0.00224

    D50 0.500

    D84 20.6

    d (mm)

    d16 0.00224

    d50 0.5

    d84 20.6

    d16 d50 d84

    Mixed Sand and Gravel Beds (cont.)Mixed Sand and Gravel Beds (cont.)Mixed Sand and Gravel Beds (cont.)Two Bed Materials

    60

    Two Bed Materials

  • 7/26/2019 Fluvial Geomorphology.pdf

    83/84

    8383

    0

    10

    20

    30

    40

    50

    60

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    log D

    Wfiner(gm)

    Gravel Sand

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10(d)

    0

    10

    20

    30

    40

    50

    60

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    log D

    Wfiner(gm)

    Gravel Sand

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10(d)

    Two Bed Materials

    -2

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    2.5

    3

    -10 -5 0 5 10norminv(P/100)

    logD

    Sand Gravel

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10

    (d)

    NORMINV(P/100)

    Two Bed Materials

    -2

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    2.5

    3

    -10 -5 0 5 10norminv(P/100)

    logD

    Sand Gravel

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10

    (d)

    NORMINV(P/100)

    Mixed Sand and Gravel Beds (cont.)Mixed Sand and Gravel Beds (cont.)Mixed Sand and Gravel Beds (cont.)Combined

    100

    Combined

    100

  • 7/26/2019 Fluvial Geomorphology.pdf

    84/84

    8484

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    log D

    WFiner(gm)

    Sand GravelD50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10(d)

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    -1.5 -1 -0.5 0 0.5 1 1.5 2

    log D

    WFiner(gm)

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10(d)

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Combined

    -2

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    -8 -6 -4 -2 0 2 4

    norminv(P/100)

    lo

    g

    D

    log D50 D50(mm)

    0.537 3.44

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log

    10

    (d)

    log10(d50) d50 (mm)

    0.537 3.44

    Combined

    -2

    -1.5

    -1

    -0.5

    0

    0.5

    1

    1.5

    2

    -8 -6 -4 -2 0 2 4

    norminv(P/100)

    log

    D

    log D50 D50(mm)

    0.537 3.44

    Sand Gravel

    D50 0.4 10

    g 1.5 2

    W (gm) 40 50

    Sand Gravel

    d50 0.4 10

    g 1.5 2

    W (gm) 40 50

    log10

    (d)

    log10(d50) d50 (mm)

    0.537 3.44