Project File:Saturated Groundwater Flow – Optional

3.9.1 Required Inputs

These cards are REQUIRED to perform 2-D lateral groundwater simulations.

CARD	Argument	Units	Description
WATER_TABLE "filename.wte"	file name		Specifies the simulation of the effect of the water table on the RE solver, gives GRASS ASCII map name of starting groundwater surface elevations (m).
GW_SIMULATION	none		Specifies the simulation of 2-D groundwater flow. INF_RICHARDS or INF_REDIST required.
GW_TIME_STEP ##.##	real	s	Time step for groundwater computations
GW_LSOR_CON ##.##	real	m	Convergence criteria for LSOR calculations. Required with INF_RICHARDS only.
AQUIFER_DELTA_Z ##.##	real	m	Size of unsaturated cell to use in all cells below the soil column specified in the SOIL_LAYER_INPUT_FILE or Mapping Table. Required with INF_RICHARDS only
GW_RELAX_COEFF ##.##	real	none	Factor to over-relax or under-relax next estimate in LSOR calculations. Required with INF_RICHARDS only. Values greater than 1.0 over-relax, values less than 1.0 under-relax. Increase value to speed solution. Decrease value when solution doesn't converge.
AQUIFER_BOTTOM "filename.bot"	file name	name	Name of GRASS ASCII map of bedrock elevations (m).
GW_BOUNDFILE "filename.bnd"	file name	name	Name of GRASS ASCII map that contains the boundary type of each cell. (0) no flow (1) no boundary, regular infiltration cell (2) specified head, taken from WATER_TABLE file (3) dynamic flux (well), not yet available (4) river with calculated flux to/from groundwater (5) river with specified head, value from channel solver (6) static flux (well), value taken from GW_FLUX_BOUNDTABLE (7) reservoir

3.9.2 Optional Inputs

Card	Argument	Units	Default	Description
GW_ASSIGN_THETA	none			When simulating saturated groundwater, assign initial values of moisture in each cell of the unsaturated zone using values in the SOIL_LAYER_INPUT_FILE. Used only with INF_RICHARDS See note below.
GW_UNIF_POROSITY	real			Uniform porosity to be used in every cell in the groundwater problem
GW_POROSITY_MAP "filename.por"	file name			Name of GRASS ASCII map containing porosity values for each cell See note below
GW_UNIF_HYCOND ##.##	real	cm/hr		Uniform hydraulic conductivity used in every cell in the groundwater problem See note below
GW_HYCOND_MAP "filename.hyd"	file name			Name of GRASS ASCII map containing hydraulic conductivity (cm hr^-1) values for each cell in the groundwater problem See note below
K_RIVER ##.##	real	cm/hr		Hydraulic conductivity (cm hr^-1) of streambed material. Use in conjunction with CHAN_EXPLIC and GW_BOUNDFILE type 4. May also be distributed in CHAN_INPUT file.
M_RIVER ##.##	real	cm		Depth of streambed material (m). Use in conjunction with CHAN_EXPLIC and GW_BOUNDFILE type 4. May also be distributed in CHAN_INPUT file.
GW_FLUXBOUNDTABLE "filename.flx"	file name			Input ASCII file containing location and pumping rate of wells in the grid. Locations should correspond to GW_BOUNDFILE.
GW_LEAKAGE_RATE ##.##	real	cm/hr	0.0	Rate of water loss out of the bottom of the shallow aquifer.
SINGLE_UNSAT_SAT ##.##	real	fraction	0.75	Fraction of soil saturation for the unsaturated groundwater media when using GAR

Values for porosity (θ_s) and saturated hydraulic conductivity (K_s) may be specified in one of four (4) ways:

Without specifying one of the two types of cards above, θ_s and/or K_s values for each cell will be assigned the value of bottom layer of the SOIL_LAYER_INPUT_FILE for the soil type as specified in the SOIL_TYPE_MAP.
Uniform values of θ_s or K_s may be specified using the appropriate card above.
GRASS ASCII maps of θ_s or K_s values for each cell may be assigned by using the appropriate card above.
Values may be assigned in the MAPPING_TABLE

3.9.3 Optional Output

CARD	Argument	Description
GW_OUTPUT "filename.gw"	file name	Filename to output groundwater head (m) MAP_TYPE maps every MAP_FREQ time steps.
OUT_WELL_LOCATION "filename.iwl"	file name	Input ASCII file containing the locations of observation wells. Values of groundwater head at each location in the file specified in OUT_WELL_LOCATION will be output every MAP_FREQ time steps in the GW_WELL_LEVEL file.
GW_WELL_LEVEL "filename.owl"	file name	File name to output groundwater heads every HYD_FREQ time steps at locations specified in OUT_WELL_LOCATION.
IN_GWFLUX_LOCATION "filename.igf"	file name	Name of input ASCII file containing the link/node pairs to write out stream/groundwater exchange flux ordinates to the file specified by OUT_GWFLUX_LOCATION.
OUT_GWFLUX_LOCATION "filename.ogf"	file name	File name to ouput stream groundwater exchange flus (m² s^-1) at locations specified in IN_GWFLUX_LOCATION file every HYD_FREQ minutes. Requires CHAN_EXPLIC or DIFFUSIVE_WAVE, CHAN_CON_TRANS, and IN_GWFLUX_LOCATION