Model Configuration

HydroPol2D is configured primarily through General_Data.xlsx. That spreadsheet selects the process stack, the routing family, the groundwater timing controls, the input files, and the optional diagnostics.

Configuration pages and theory pages serve different roles:

• theory explains what each module does;
• configuration explains which public controls expose that behavior.

Current configuration logic

The public configuration story should match the implemented model:

• layered vadose storage and groundwater coupling are the default pathway when groundwater is active;
• the routing family includes local inertial, full momentum, diffusive D4, kinematic D4, and cellular automata;
• only one major routing family should be active at a time.

Capability and maturity

Capability	Main public controls	Current status
Hydrologic core	flag_infiltration, ET/rainfall/snow controls, soil/LULC tables	Default + validated
Layered groundwater recharge and async scheduler	flag_groundwater_modeling, flag_groundwater_async, groundwater_target_dt_min, groundwater_min_dt_min, groundwater_max_head_change_m, groundwater_courant	Default + validated
Capillary rise	flag_capillary_rise	Optional + validated in controlled benchmarks
Local inertial routing	flag_inertial, flag_numerical_scheme	Default + validated
Full-momentum routing	flag_full_momentum	Optional + validated in controlled benchmarks
Diffusive routing	flag_diffusive	Optional + validated in controlled benchmarks
Kinematic routing	flag_kinematic	Optional + validated in controlled benchmarks
Cellular automata routing	flag_CA	Optional + validated for conservation/routing bookkeeping
Human instability	flag_human_instability	Optional + validated for implemented modes 1 and 3

Main configuration domains

1. Simulation and forcing control

General_Data.xlsx defines simulation timing, rainfall and meteorological forcing, inflow and stage boundaries, output cadence, and runtime options such as adaptive time stepping or GPU execution.

2. Routing-family selection

The current public routing interface includes:

• flag_inertial
• flag_full_momentum
• flag_diffusive
• flag_kinematic
• flag_CA

Only one of these major routing flags should be active in a given run. D8 exists as a secondary pathway, but it should not be documented as a parallel theory family to the main shallow-water and D4 options.

3. Groundwater controls

When groundwater modeling is active, HydroPol2D now exposes behavior that should be documented explicitly:

• asynchronous saturated-groundwater updates;
• head-change-triggered groundwater solves;
• explicit groundwater stability capping;
• optional capillary rise;
• lateral Boussinesq flow when baseflow is active.

4. Hazard and water-quality diagnostics

Optional modules such as water quality and human instability are controlled through their own flags and parameter sections. For human instability specifically, the public docs should reflect that:

• mode 1 is implemented;
• mode 3 is implemented;
• mode 2 is not implemented.

Recommended reading of a configuration

For most public-facing HydroPol2D runs, readers should be able to infer:

1. which routing family is active;
2. whether groundwater is coupled only locally or also laterally through Boussinesq flow;
3. whether capillary rise is enabled;
4. whether human-instability or water-quality diagnostics are enabled.

If those four questions are clear, the configuration is aligned with the current model story.