System Scope And Assumptions#

Purpose#

This page is a first scaffold for the project-level scientific narrative that is still largely missing from the published documentation.

Its long-term role should be to answer one question clearly:

“What kind of hydrological and hydrogeological system is HydroModPy designed to model?”

Current Scientific Target#

HydroModPy is currently oriented toward:

  • catchment-scale shallow groundwater systems,

  • mostly unconfined or weakly confined near-surface aquifers,

  • domains where topography, hydrography, and geology strongly organize groundwater flow,

  • workflows that combine spatial preprocessing, forcing preparation, groundwater simulation, validation, and comparison.

In practical terms, the repository is centered on the deployment and comparison of groundwater-flow models on synthetic and geographic catchments rather than on fully coupled land-surface or regional deep-basin modelling.

Main Scientific Chain#

At a high level, the intended scientific chain is:

climate or recharge information
-> hydrological preprocessing or direct recharge forcing
-> solver-agnostic groundwater problem
-> concrete numerical backend
-> postprocessed heads, fluxes, budgets, and diagnostics
-> validation or calibration against references and observations

Shared Assumptions That Should Be Made Explicit#

Several assumptions are already embedded in the code, but they are not yet collected in one visible scientific page.

The shared assumptions currently include at least:

  • a strong focus on shallow groundwater and catchment response,

  • hydraulic properties driven by geology and spatial supports,

  • geometry derived from topography, substratum, and optional runtime meshes,

  • solver-dependent handling of groundwater/surface interaction,

  • a distinction between project-level scientific payloads and backend-specific numerical representations.

Just as important, these assumptions are not identical across all backends. Some are shared at the [flow] level, while others only become true once one solver family is chosen.

What This Page Should Eventually Document#

This page should later be expanded into a compact but explicit project-level reference covering:

  1. Physical domain: catchment, aquifer thickness, role of topography, hydrography, and geology.

  2. Water inputs and outputs: recharge, evapotranspiration, wells, stream and ocean interactions, drainage, saturation excess where applicable.

  3. State variables: hydraulic head, saturated thickness, storage-related quantities, derived discharge metrics.

  4. Scale assumptions: when HydroModPy is a good fit, and when it is not.

  5. Backend envelope: what remains solver-agnostic versus what depends on MODFLOW-NWT, MODFLOW 6, or the in-house Boussinesq backend.

Current Source Anchors#

Useful code and documentation anchors for the future expansion are:

Current Documentation Gap#

Today, HydroModPy already documents software layers fairly well, but the project-level scientific frame is still implicit and dispersed across:

  • solver notes,

  • validation-case descriptions,

  • capability-gallery pages,

  • developer design notes.

This page exists to turn that implicit knowledge into one canonical scientific entry point.