Solvers#
Scientific content behind the HydroModPy solver layer. Focuses on what each solver represents mathematically and which numerical choices are active, not on the runtime orchestration.
Operational pages live elsewhere
For backend selection and TOML snippets, see Solvers. For the package layout and runtime handoff, see Solver Architecture. The in-house Boussinesq theory is in Boussinesq Theory.
MODFLOW family#
Reading map for MODFLOW 6 and MODFLOW-NWT in HydroModPy: common contract, backend split, comparison discipline, and version-specific emphasis.
Cell-by-cell groundwater balance, control-volume finite difference statement, sign conventions, and the relationship to the solver-agnostic problem.
How HydroModPy maps the [flow] payload to NPF, STO, RCHA,
WEL, CHD, DRN, and EVT packages, with version differences
flagged explicitly.
Scientific contrast of the two MODFLOW backends: support, solver settings, package coverage, transport coupling, and reasons to keep both alive.
Why XT3D matters when a DISV-style mesh leaves the strictly-orthogonal regime, with the method-choice evidence published in the gallery.
MODFLOW 6-specific notes for flow/modflow6: structured and
runtime DISV support, XT3D policy, and the GWT downstream
route.
MODFLOW-NWT-specific notes for flow/modflow_nwt: legacy
structured sgrid continuity, MODPATH and MT3DMS
compatibility.
Checklist to follow before attributing a difference between
flow/modflow6 and flow/modflow_nwt to the numerical
backend.
Mesh and discretization#
The separation between physical problem, planar support, vertical layering, and solver-specific cell interpretation.
How heterogeneous fields (geology, hydraulic conductivity, forcing) are projected to solver cells across mesh families.
How vertical layering and saturated thickness assumptions shape storage, transmissivity, and the unconfined response.
Quality diagnostics that decide whether a discretization is acceptable before solver results are trusted.
Worked cases and reference matrix#
Executable MODFLOW-family examples that link assumptions to TOML inputs, package assembly, and inspected outputs.
The simplest analytical-style benchmark: Dupuit unconfined flow against fixed-head boundaries in a 1D strip.
Linearized unconfined response to a periodic recharge signal, with explicit comparison against the analytical solution.
The Nancon basin transient MODFLOW-NWT case with ETP routed through the EVT package, the canonical real-basin teaching reference.
Which downstream transport solver consumes each MODFLOW-family flow field: MODFLOW 6 GWT, MODPATH, or MT3DMS.
Compact inventory of what each solver can represent today and where the active development edges sit.