gwflow

Purpose¶

The gwflow module writes its own set of output files when bsn_cc%gwflow = 1 in codes.bsn. Outputs are toggled in print.prt via six rows: gwflow_wb, gwflow_flux, gwflow_heat, gwflow_solute, gwflow_obs, gwflow_pump. Each row has the standard daily/monthly/yearly/average-annual flags.

Source¶

Writer: src/gwflow_output.f90
Types: src/gwflow_module.f90, type groundwater_ss for fluxes
Simulation-time writes (cell-level): src/gwflow_simulate.f90

Output files¶

Water balance¶

File	Scope	Aggregation
`gwflow_basin_wb_day.txt`	basin total	daily
`gwflow_basin_wb_mon.txt`	basin total	monthly
`gwflow_basin_wb_yr.txt`	basin total	yearly
`gwflow_basin_wb_aa.txt`	basin total	annual average
`gwflow_cell_wb_day.txt`	per cell	daily
`gwflow_cell_wb_mon.txt`	per cell	monthly
`gwflow_cell_wb_yr.txt`	per cell	yearly
`gwflow_cell_wb_aa.txt`	per cell	annual average

Columns (in declaration order from type groundwater_ss, units m^3):

#	Name	Description
1	chng	change in storage (grid summaries only)
2	rech	recharge
3	gwet	groundwater ET
4	gwsw	groundwater discharge to channels
5	swgw	channel seepage to groundwater
6	satx	saturation excess flow
7	soil	groundwater added to the soil profile
8	latl	lateral flow between cells
9	disp	dispersion (heat and solute transport)
10	bndr	boundary exchange
11	ppag	allocation-driven pumping (irrigation)
12	ppdf	pumping deficit (unmet demand)
13	ppex	external pumping
14	tile	tile drainage outflow
15	resv	reservoir exchange
16	wetl	wetland exchange
17	fpln	floodplain exchange
18	canl	canal exchange
19	pond	recharge pond seepage
20	phyt	phreatophyte transpiration
21	totl	sum of inputs and outputs

Per-cell files prepend a cell id and timestamp; basin files aggregate across all cells.

Heat¶

When the heat transport sub-module is active (gwflow.heat is present), the following are written:

File	Aggregation
`gwflow_basin_heat_day.txt`	daily
`gwflow_basin_heat_yr.txt`	yearly
`gwflow_basin_heat_aa.txt`	annual average

Columns are the same fields as water balance, reinterpreted as heat fluxes (the writer reuses type groundwater_ss). Refer to the model theory page on Aquifers for the heat transport equations.

Solutes¶

When solute transport is active (gwflow.solutes listing constituents), per-species water-balance-style files are written. Six species are emitted directly by the writer:

Species	Files
Calcium (`ca`)	`gwflow_basin_sol_ca_{day,mon,yr,aa}.txt`
Chloride (`cl`)	`gwflow_basin_sol_cl_{day,mon,yr,aa}.txt`
Potassium (`k`)	`gwflow_basin_sol_k_{day,mon,yr,aa}.txt`
Magnesium (`mg`)	`gwflow_basin_sol_mg_{day,mon,yr,aa}.txt`
Sodium (`na`)	`gwflow_basin_sol_na_{day,mon,yr,aa}.txt`
Phosphorus (`p`)	`gwflow_basin_sol_p_{day,mon,yr,aa}.txt`

Columns follow the same groundwater_ss field set, interpreted as solute mass fluxes (kg).

Cell definition¶

gwflow_cell_definition.txt is written once at the start of the run. It maps the grid coordinates to cell IDs and is the key for interpreting any per-cell output.

Always-on log¶

gwflow_record is a plain-text log opened when bsn_cc%gwflow = 1. The simulation banner and per-feature notes are written there. Useful for confirming the gwflow module activated and which sub-features (pumps, ponds, tiles, etc.) loaded.

print.prt toggles¶

Toggle	Files produced
`gwflow_wb`	basin and cell water balance
`gwflow_flux`	gwflow canal, pond, tile, gwsw, channel observation diagnostics
`gwflow_heat`	basin heat balance
`gwflow_solute`	basin solute balance for each species
`gwflow_obs`	observation well output (when `gwflow.hru_pump_observe` or observation file is set)
`gwflow_pump`	per-HRU pumping output

The aggregation flags on each row (d, m, y, a) control which suffix variants are written.