[modflow6] Modflow6Config

TOML section: [modflow6]

Pydantic model: Modflow6Config defined in hydromodpy.solver.modflow6.modflow6_config.

Source on GitHub

Expert-level MODFLOW 6 configuration organized by concern.

Show fields: User User + Dev All

Fields

runtime in TOML: [modflow6.runtime]

Modflow6RuntimeConfig factory expert source

MODFLOW 6 runtime options.

Fields of Modflow6RuntimeConfig

mf6_executable_name

str default = “mf6” expert source

MODFLOW 6 executable name or absolute path.

mf6_ims_complexity

Literal[‘SIMPLE’, ‘MODERATE’, ‘COMPLEX’] default = “COMPLEX” expert source

IMS complexity preset for MODFLOW 6: SIMPLE, MODERATE, or COMPLEX.

mf_verbose

bool default = False expert source

Enable verbose FloPy logging for MODFLOW 6 setup and execution.

mf6_outer_dvclose

float default = 0.0001 expert source

IMS outer-iteration head-change convergence criterion.

mf6_inner_dvclose

float default = 0.0001 expert source

IMS inner-iteration head-change convergence criterion.

mf6_outer_maximum

int default = 500 expert source

Maximum number of IMS outer iterations.

mf6_inner_maximum

int default = 500 expert source

Maximum number of IMS inner iterations.

mf6_inner_rclose

Optional[float] default = None expert source

IMS inner-iteration flow-residual closure (L^3/T in run units). None keeps the complexity-preset default.

mf6_linear_acceleration

Optional[Literal[‘CG’, ‘BICGSTAB’]] default = None expert source

IMS linear acceleration: CG for symmetric matrices, BICGSTAB for the non-symmetric Newton formulation. None keeps the preset default.

mf6_under_relaxation

Optional[Literal[‘NONE’, ‘SIMPLE’, ‘COOLEY’, ‘DBD’]] default = None expert source

IMS non-linear under-relaxation scheme. DBD is recommended with Newton. None keeps the preset default.

mf6_enable_rewet

bool | None default = None expert source

Enable NPF cell rewetting. When left to None, HydroModPy keeps rewetting disabled unless explicitly enabled.

mf6_newton

bool default = True expert source

Enable the MODFLOW 6 Newton-Raphson formulation. Catchment cells are always convertible (unconfined), so Newton with under-relaxation is the robust default and matches the MODFLOW-NWT backend.

mf6_newton_under_relaxation

bool default = True expert source

Enable MODFLOW 6 Newton under-relaxation when mf6_newton is true.

mf6_enable_xt3d

bool | None default = None expert source

Enable MF6 NPF XT3D terms. When left to None, HydroModPy auto-enables XT3D on unstructured solver meshes. This increases computational cost but can improve accuracy on unstructured or non-orthogonal grids.

mf6_rewet_wetfct

float default = 0.1 expert source

MF6 NPF rewet WETFCT factor.

mf6_rewet_iwetit

int default = 1 expert source

MF6 NPF rewet IWETIT interval.

mf6_rewet_ihdwet

int default = 0 expert source

MF6 NPF rewet IHDWET flag.

mf6_rewet_wetdry

float default = 0.1 expert source

MF6 NPF WETDRY threshold used when rewetting is active.

process_specific in TOML: [modflow6.process_specific]

Modflow6ProcessSpecificConfig factory expert source

Process-specific controls for MODFLOW 6 flow packages.

Fields of Modflow6ProcessSpecificConfig

vka

float default = 1.0 expert source

Vertical anisotropy ratio kh/kv (dimensionless, > 0). k33 = k / vka.

evt_extinction_depth

float default = 1.0 expert source

Meters; extinction depth for the EVT sink used when recharge negatives are routed to EVT. The routed deficit tapers linearly from the cell top to this depth and stops below it, so a sustained climatic deficit can saturate near this value.

sgrid in TOML: [modflow6.sgrid]

SolverSGridConfig factory user source

Solver-grid payload split into planar and vertical sections.

Fields of SolverSGridConfig

planar in TOML: [modflow6.sgrid.planar]

PlanarGridConfig factory user source

Planar discretization of the solver grid.

Fields of PlanarGridConfig

mode

Literal[‘keep_native’, ‘resample_to_shape’] default = “keep_native” user source

Planar solver-grid mode: keep the native domain support or resample to an explicit (ny, nx) target shape.

nx

Optional[int] default = None user source

Target number of columns when planar mode is ‘resample_to_shape’.

ny

Optional[int] default = None user source

Target number of rows when planar mode is ‘resample_to_shape’.

resampling

Literal[‘bilinear’, ‘average’, ‘nearest’] default = “bilinear” dev source

Resampling rule applied when planar mode is ‘resample_to_shape’.

vertical in TOML: [modflow6.sgrid.vertical]

VerticalGridConfig factory user source

Vertical layering of the solver grid.

Fields of VerticalGridConfig

genmtd_lay

Literal[‘constant’, ‘decay’, ‘list’] default = “constant” user source

Vertical-layering strategy.

nlay

int | None default = 1 user source

Number of layers (required for constant/decay, ignored for list).

lay_decay

float | None default = None dev source

Decay exponent (>1) for decay layering.

lay_proportions

list[float] | None default = None dev source

Explicit layer fractions when genmtd_lay=’list’ (must sum to 1).

nodata

float default = -9999.0 dev source

No-data sentinel value.

Starter TOML snippet

Click to expand a copy-pasteable [modflow6] TOML skeleton

Copy this block into your project.toml and uncomment the lines you want to set. Sub-tables ([parent.subfield]) appear in the order Pydantic expects them.

[modflow6]

[modflow6.sgrid]
# planar = ...  # factory default
# vertical = ...  # factory default

Cases using this section

Validation gallery cases that reference fields from this section:

• Boussinesq Circular-Island Piecewise-K 2D

• Boussinesq Divide-Fixed-Head Piecewise-K 1D

• Boussinesq Fixed-Head Piecewise-K 1D

• Boussinesq Sloping-Substratum Constant-Thickness 1D

• Boussinesq Sloping-Substratum Fixed-Head 1D

• Boussinesq Sloping-Substratum Uniform-Recharge 1D

• Boussinesq Uniform-Recharge Piecewise-K 1D

• Brutsaert Recession Validation: Thin Nonlinear Aquifer

• Brutsaert Recession Validation: Deep Linearized Aquifer

• Dupuit Circular-Island Ocean 2D

• Dupuit Divide-River 1D

• Dupuit Fixed-Head 1D

• Dupuit Uniform Recharge 1D

• Late-Time Unconfined Pumping 2D

• Linearized Unconfined Boundary Piecewise 1D

• Linearized Unconfined 1D Boundary Step

• Linearized Unconfined Drainage 1D

• Linearized Unconfined Hillslope Drainage 1D

• Linearized Unconfined 1D Periodic Recharge

• Linearized Unconfined 1D Recharge Step

• Linearized Unconfined 1D Recharge Step (Deep Aquifer)

Entity-relationship diagram

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