Configuration Variable Index

Note

For a full walkthrough of each configuration block with examples, see Configuration Reference.

Short, alphabetized reference for all configuration variables. Each row links to the section where it is explained.

---

Configuration variables (A–Z)

Variable	Section	Details
checkpoint_id	Simulation Control	Restart index. 0 means fresh start, greater than 0 restarts from that checkpoint.
const_mann	Surface Roughness (Manning’s n)	Constant Manning’s n for the entire domain if no raster is provided.
courant	Miscellaneous Parameters	CFL number. Keep at or below 0.5.
dem_filename	Topography	Path to the DEM raster that defines the grid for all other rasters.
domain_decomposition	Miscellaneous Parameters	Partitioning mode for parallel runs: static or dynamic.
extbc_dir	External Boundaries	Optional directory containing files referenced by extbc_file.
extbc_file	External Boundaries	Table of external boundary segments and parameters.
factor_interval_domain_decomposition	Miscellaneous Parameters	Update frequency used when domain decomposition is dynamic.
gpu_direct_flag	Miscellaneous Parameters	CUDA aware MPI toggle. 0 off, 1 on.
h_infile	Initial Conditions	Initial water depth raster. Optional.
hextra	Miscellaneous Parameters	Depth tolerance in meters below which velocities are set to zero.
hydrograph_filename	Hydrologic Forcing	Streamflow hydrographs. First column is time in hours, others are discharges in m³/s.
input_format	Input and Output Formats	Input raster format: ASC or BIN.
it_count	Miscellaneous Parameters	Internal counter, usually left at 0.
it_print	Output Control	Iteration interval for diagnostic log messages.
n_infile	Surface Roughness (Manning’s n)	Raster of Manning’s n values aligned with the DEM.
num_extbc	External Boundaries	Number of external boundary segments.
num_runoffs	Hydrologic Forcing	Number of runoff zones in the domain.
num_sources	Hydrologic Forcing	Number of streamflow inflow points.
observation_loc_file	Output Control	XY locations for time series outputs, in projected meters.
open_boundaries	Miscellaneous Parameters	Global switch to open domain edges; ignored when explicit boundaries are defined.
outfile_pattern	Input and Output Formats	Naming convention for output files.
output_format	Input and Output Formats	Output raster format: ASC, BIN, or GTIFF.
output_option	Input and Output Formats	Parallel output mode: SEQ single files, PAR per subdomain.
print_interval	Output Control	Time in seconds between raster outputs.
print_observation	Output Control	Switch to write observation outputs.
print_option	Output Control	Which raster fields to output: h or huv.
projection	Input and Output Formats	EPSG or WKT used only when writing GTIFF outputs.
qx_infile	Initial Conditions	Initial x discharge raster. Optional.
qy_infile	Initial Conditions	Initial y discharge raster. Optional.
runoff_filename	Hydrologic Forcing	Runoff hydrographs. First column is time in hours, others are mm/hr per zone.
runoff_map	Hydrologic Forcing	Raster of runoff zone IDs aligned with the DEM.
sim_duration	Simulation Control	Total simulation length in seconds.
sim_start_time	Simulation Control	Start time in seconds.
src_loc_file	Hydrologic Forcing	XY coordinates for inflow sources that match hydrograph column order.
time_increment_fixed	Simulation Control	0 uses adaptive timestep, 1 uses fixed timestep.
time_series_flag	Output Control	1 enables time series outputs at observation points.
time_step	Simulation Control	Fixed timestep in seconds used when time_increment_fixed = 1.