This command allows you to change some settings that affect the way your simulation works.
The follow options are available:
When the Reset Duration At Restart check box is cleared, you can restart or reset a simulation without changing the start and end times for the simulation. Selecting this option will always remove the duration parameters when you restart or reset the simulation, you will then provide new start and end times for subsequent simulations.
When selected, this option will restore your ignitions and barriers when the simulation is restarted (not reset, see Simulation > Start/Restart and Simulation > Reset) The ignitions and barriers will be restored as they existed at the beginning of the simulation. If the check box is cleared, you must enter new ignitions and barriers for subsequent simulations.
When this check box is cleared, all ignitions will produce outward burning fires (e.g. fires increasing in area or expanding outward). Polygon ignitions are screened for the rotation direction in which they were created (clockwise or counterclockwise) and reversed if found to be oriented clockwise. This screening and correction process is bypassed when this option is selected and allows you to produce inward and outward burning fire polygons. COUNTERCLOCKWISE polygons will burn outward, and CLOCKWISE polygons will burn inward.
This option only affects the display of fire growth not the simulation process. When this check box is selected (the default) the simulation will draw fire perimeter growth as it is calculated (i.e. when more than one fire is simulated, fires will appear to grow one-at-a-time). Clearing this check box will display growth of all fires simultaneously by delaying drawing until a time step is completed.
Point ignitions in FARSITE are assumed to have a initial spread rate of zero. However, if your simulation ignition is a line or polygon, the assumption is that the simulated fire is already burning and would have a current rate of spread (ROS).
Selecting this check box allows setting the current rate of spread when setting polygon or line ignitions. This affects the starting value of spread rate for fire acceleration in the subsequent time step.
Clearing this check box gives polygon or line ignitions a default initial spread rate at 100% of the equilibrium ROS.
See Simulate > Modify Map > Locate Ignitions for more information.
When a simulated fire burns around a rock or lake it create a inactive enclave (inward burning fire). If a simulation has very many of these inactive enclaves, FARSITE will spend a lot of time on them, even though they are not contributing to the simulated fire behavior. Selecting this option will remove these inactive enclaves and speed up the simulation. However these enclaves will then be included in the fire area statistics.
If you have a multi-processor computer you can decide how many processors the simulation can use. This number cannot be more than the number of processors in your computer.
Normally, to run the simulation as fast as possible you should set the number of threads equal to the number of processors. But if you want to use another application on your computer while the simulation is running you should reduce the number of simulation threads to less than the number of processors.
FARSITE can use up to 64 simulation threads although performance will probably not improve for most simulations beyond 4 or 8 processors.