Sensitivity Periods

FPA-PM divides the year into a maximum of 26 sensitivity periods, corresponding to each two-week period in the calendar year. The two-week period is the minimum resolution needed to capture the temporal differences in fire behavior and effects on objectives, constraints, and resources. By using sensitivity periods, you can refine the analysis to accommodate the changing conditions that occur throughout the year.

For example, you may have an area that needs to be aggressively protected during nesting season, but later in the year, you may want to manage the same area for wildland fire use. Using the sensitivity periods, you can reflect this change in management objectives.

As another example, your FMU may have a split fire preparedness season, which needs to be reflected in your resource allocation. By aggregating the periods to form longer time blocks, you can use the sensitivity periods to identify which time blocks apply to each fire preparedness season.

Where Sensitivity Periods are Used:

Sensitivity periods are used in several areas of FPA-PM. Click the appropriate link for more information about how sensitivity periods work with each item listed <<blue text like this equals online only info>:

• Establishing FMU Objectives (coming in version 1.3)
• Establishing Constraints
• Grouping FMUs by Objective (coming in version 1.3)
• Determining Weights
• Understanding the ERCg Calculation in PCHA
• Defining the Fire Preparedness Season
• Establishing Fire Resource Limitations

Critical Data Needed for Sensitivity Periods

Before working with sensitivity periods in FPA-PM, you need to develop the following information for each FMU:

• Determine your fire preparedness season(s).
• Determine your management objectives and constraints, including which objectives and constraints apply to multiple FMUs.
• Determine which constraints apply during each sensitivity period.
• Identify how fire intensity level (FIL) affects your response for each sensitivity period.
• Identify what equipment types are constrained for use.
• Establish the rationale for the constraint (e.g., cite law, policy, or land management issue that the restriction is based on)

Relationship to Fire Intensity Level

In any Fire Management Unit (FMU), the designation of fire as beneficial or detrimental can vary depending on both the time of year and/or the FIL <<insert link to FIL section>>. FPA is designed to accommodate this variability.

For example, a low intensity fire (level 1-2) in an old-growth ponderosa forest might be managed as wildland fire use most of the year, except during nesting season. However, a high intensity fire (level 3 or higher) any time of the year would require a suppression response for that FMU. FPA enables you to designate these different responses by both sensitivity period and the FIL.

Relationship to Weights

Weights <<insert link to weight section>> reflect important differences for each sensitivity period and FIL relative to other FMUs within the same period. The weighting process enables you to quantify the importance of protecting one area of land relative to another at each FIL and sensitivity period.

For example, you may need to protect an area from moderate FILs early in the season, while it might be less important to protect it later in the season. The weighting process enables you to quantify this relative importance.<<what about multiple ignitions? doesn't the weighting process also enable you to determine what response you will have to each one? Is there a more specific example?>>

Related Topics

For more information, see the following topics:

• Fire Intensity Levels
• Weighting
• Fire Preparedness Season
• Land Management Objectives
• Constraints
• ERCg calculations in PCHA
• Fire Resource Limitations