Sediment Component¶

The Sediment component controls sediment transport, morphological updating, bed composition, and groundwater flow.

Overview¶

from rompy_xbeach.components.sediment import Sediment
from rompy_xbeach.components.sediment.transport import SedimentTransport
from rompy_xbeach.components.sediment.morphology import Morphology
from rompy_xbeach.components.sediment.composition import BedComposition
from rompy_xbeach.components.sediment.bed import BedUpdate
from rompy_xbeach.components.sediment.groundwater import GroundwaterFlow

sediment = Sediment(
    sedtrans=SedimentTransport(form="vanthiel_vanrijn"),
    morphology=Morphology(morfac=10),
    bed_composition=BedComposition(D50=0.0002),
)

Sub-Components¶

Sediment Transport¶

Controls the sediment transport formulation:

from rompy_xbeach.components.sediment.transport import SedimentTransport

transport = SedimentTransport(
    # Transport formulation
    form="vanthiel_vanrijn",

    # Wave shape effects
    waveform="vanthiel",

    # Stirring mechanisms
    turb="wave_averaged",  # Turbulence formulation
    sws=True,              # Short wave stirring
    lws=True,              # Long wave stirring
    lwt=False,             # Long wave turbulence

    # Calibration factors
    facua=0.1,             # Onshore transport factor
    facAs=0.1,             # Skewness factor
    facSk=0.1,             # Asymmetry factor
)

Transport formulations (form):

Value	Description
`soulsby_vanrijn`	Soulsby-Van Rijn (1997)
`vanthiel_vanrijn`	Van Thiel-Van Rijn (2009)
`vanrijn1993`	Van Rijn (1993)

Wave shape formulations (waveform):

Value	Description
`ruessink_vanrijn`	Ruessink et al. (2012)
`vanthiel`	Van Thiel de Vries (2009)

Turbulence formulations (turb):

Value	Description
`bore_averaged`	Bore-averaged turbulence
`wave_averaged`	Wave-averaged turbulence
`none`	No turbulence

Morphology¶

Controls morphological acceleration and timing:

from rompy_xbeach.components.sediment.morphology import Morphology

morphology = Morphology(
    morfac=10,           # Morphological acceleration factor
    morstart=3600,       # Start morphology after 1 hour (s)
    morstop=86400,       # Stop morphology after 1 day (s)

    # Avalanching
    wetslp=0.3,          # Critical wet slope
    dryslp=1.0,          # Critical dry slope

    # Structures
    struct=False,        # Enable structures
    ne_layer=None,       # Non-erodible layer file
)

Key parameters:

Parameter	Description	Default
`morfac`	Morphological acceleration factor	1
`morstart`	Time to start morphology (s)	0
`morstop`	Time to stop morphology (s)	tstop
`wetslp`	Critical wet slope for avalanching	0.3
`dryslp`	Critical dry slope for avalanching	1.0

Bed Composition¶

Defines sediment properties:

from rompy_xbeach.components.sediment.composition import BedComposition

bed = BedComposition(
    # Grain sizes (lists for each sediment class)
    D50=[0.0002],        # Median grain size (m)
    D90=[0.0003],        # 90th percentile (m)
    D15=[0.00015],       # 15th percentile (m)

    # Multiple grain classes
    ngd=1,               # Number of grain classes

    # Sediment properties
    rhos=2650,           # Sediment density (kg/m³)
    por=0.4,             # Porosity

    # Bed layers
    nd=3,                # Number of bed layers
    dzg1=0.1,            # Top layer thickness (m)
    dzg2=0.1,            # Middle layer thickness (m)
    dzg3=0.1,            # Bottom layer thickness (m)

    # Calibration
    sedcal=1.0,          # Sediment transport calibration
    ucrcal=1.0,          # Critical velocity calibration
)

Validation:

D90 must be greater than D50
D50 must be greater than D15 (if specified)
Grain size lists must match ngd

Bed Update¶

Controls bed level updating:

from rompy_xbeach.components.sediment.bed import BedUpdate

bed_update = BedUpdate(
    fwfile=None,         # Wave friction file
    fwcutoff=1000,       # Wave friction cutoff depth (m)
)

Groundwater Flow¶

from rompy_xbeach.components.sediment.groundwater import GroundwaterFlow

groundwater = GroundwaterFlow(
    gwflow=True,         # Enable groundwater
    gwnonh=False,        # Non-hydrostatic groundwater
    kx=0.0001,           # Horizontal permeability (m/s)
    ky=0.0001,           # Vertical permeability (m/s)
    gwheadmodel=1,       # Head boundary model
)

Complete Example¶

from rompy_xbeach.components.sediment import Sediment
from rompy_xbeach.components.sediment.transport import SedimentTransport
from rompy_xbeach.components.sediment.morphology import Morphology
from rompy_xbeach.components.sediment.composition import BedComposition
from rompy_xbeach.components.sediment.groundwater import GroundwaterFlow

sediment = Sediment(
    # Enable sediment transport with custom formulation
    sedtrans=SedimentTransport(
        form="vanthiel_vanrijn",
        waveform="vanthiel",
        turb="wave_averaged",
        sws=True,
        lws=True,
        facua=0.1,
    ),

    # Morphological acceleration
    morphology=Morphology(
        morfac=10,
        morstart=3600,
        wetslp=0.3,
        dryslp=1.0,
    ),

    # Sediment properties
    bed_composition=BedComposition(
        D50=[0.0002],
        D90=[0.0003],
        rhos=2650,
        por=0.4,
    ),

    # Groundwater (optional)
    groundwater=GroundwaterFlow(
        gwflow=True,
        kx=0.0001,
    ),
)

YAML Configuration¶

sediment:
  transport:
    form: vanthiel_vanrijn
    waveform: vanthiel
    turb: wave_averaged
    sws: true
    lws: true
    facua: 0.1

  morphology:
    morfac: 10
    morstart: 3600
    wetslp: 0.3
    dryslp: 1.0

  bed_composition:
    D50: 0.0002
    D90: 0.0003
    rhos: 2650
    por: 0.4

API Reference¶

See Sediment API Reference for the complete API documentation.