A number of graph windows can be displayed to show data changes over time. Graph windows can be opened at any time, resized, or minimized. The graph windows can be saved to a bitmap (.BMP) file or the clipboard by pressing the right mouse button on the window.
The fire area and perimeter are calculated as a horizontal projection as well as with a topologic (slope) correction. The topologic or slope value represents the surface area (for fire area) or surface distance (for fire perimeter).
Graph windows can be displayed during an active simulation so that run-time changes can be monitored. Graph windows can be opened using the Output > Graphs command or the button.
Graph of total fire area (for all fires) over time is toggled using this menu item or the area tool button. Horizontal and topologic values of fire area are displayed as a function of time. The topologic value will always be greater than the horizontal projection on sloping ground. The difference between horizontal and topologic values of fire area can become greater or stay the same, but cannot decrease over time.
Graph of the total fire perimeter (for all fires) over time is toggled using this menu item or the perimeter tool button. Unlike fire area, the horizontal and topologic values for perimeter may diverge and converge over time as the fire edge spreads to new terrain.
A Fire characteristics chart can be displayed for automatic plotting of fire front characteristics. A fire characteristics chart (Andrews and Rothermel 1982) is useful for visualizing fire behavior in terms of spread rate and heat density (heat per unit area). The product of these axes yields values of fire line intensity that are related to flame length (Byram 1959). Fire behavior values are plotted in red from all active fire fronts (if there are more than one fire) in the current time-step; these markers are replaced by yellow markers as time progresses. This feature allows you to visualize an "envelope" of fire behavior resulting from temporal and spatial changes for each fuel type involved at the fire edge. For example, fuel moisture fluctuation throughout a diurnal cycle results in movement along the X-axis; wind speed and slope affects spread rate and position along the Y-axis. Different fuel models will result in distinct clusters of points and have their own envelope of fire response to environmental conditions.
The fire characteristics chart will reflect a transition from surface to active crown fire by increasing both the heat/unit area and spread rate. Heat/unit area increases for crown fires because the fine crown fuels are added to the combustion zone. Spread rate increases because the crown fire becomes influenced by the open wind speed, not an understory wind. Thus, points on the fire perimeter that are burning as a crown fire will plot on the chart to the right of those points burning only in surface fuels. The flame length values for crown fire are more difficult to interpret than for surface fire because much of the flame is emanating from burning crown fuels that are elevated considerably above the ground surface.
If the post-frontal combustion model is enabled, a variety of heat and emission output graphs are available. Selecting the Output > Graphs > Post-Frontal Combustion command displays a default "Fuel Weight Loss Rate" graph.
Right clicking on the "Fuel Weight Loss Rate" graph bring up a shortcut menu where you can select other heat and emission output rate tables or save the graph as an bitmap image.
Note the Weather Monitoring Stations are placed using Simulate > Modify Map > Weather Monitoring and Grid command or the tool button.
Selecting the Output > Graph > Weather Monitoring Stations command brings up the "Weather Stations" dialog box:
Available Weather Monitoring Stations will have the checkbox selected in the Station column. Two graphs are available for each weather monitoring station:
fuel moisture, and
a combined temperature and humidity graph.
Select the appropriate check boxes for the tables to be displayed during the simulation.
All graph windows can be exported to a file or the clipboard by clicking the right mouse button on the window of interest and selecting the desired output from the following shortcut menu.
The Plot (Area, Perimeter, or Combustion) vs. Time function is the default output option.
Select Plot 1st (or 2nd) Deriv. vs. Time to change the plot to the First or Second Derivative of the Y-axis against time (the X-axis).
Clicking Save Bitmap Image brings up a "Save As" dialog box, then navigate to the desired folder. Name the file, FARSITE will add the .BMP extension, and click the Save button. The bitmap (.BMP) file can now be edited in a image processor (Microsoft Paint, Photoshop, etc).
Click Send Bitmap to Clipboard to place the image on the clipboard, which can then be pasted into a image processor.
Because of technical difficulties the Print Window option is not available. Instead save a bitmap image and use your image processor software to print.
The fire characteristics chart in FARSITE has adjustable X and Y axes. By moving the mouse cursor to the edges of the chart, a left button click will increase or decrease the length of the axis depending on which side you're nearest. For example, the range of the X-axis can be increased decreased by moving the mouse cursor to the far right or far left of the window, respectively, and clicking the left button. The Y-axis can be adjusted by moving to the top or bottom of the window.
Clicking on the graph will display the X and Y values from the graph.