This dataset is a product of the PNW QWRA 2025. The purpose of the PNW QWRA 2025 is to provide foundational information about wildfire risk across the Pacific Northwest Region (which encompasses the states of Oregon and Washington). Analytics from the QWRA are used to guide vegetation management, fire response, and community planning at multiple scales.

A QWRA considers several different components, each resolved spatially across the region, including:

- likelihood of a fire burning,

- the intensity of a fire if one should occur,

- the exposure of assets and resources based on their locations, and

- the susceptibility of those assets and resources

Data users are encouraged to refer to the PNW QWRA 2023 Methods Report for full details: https://oe.oregonexplorer.info/externalcontent/wildfire/PNW_QWRA_2023Methods.pdf

The PNW QWRA 2025 evaluated risk to eight highly-valued resources and assets (HVRAs): People and Property, Infrastructure, Drinking Water, Timber, Ecological Integrity, Wildlife Habitat, Agriculture, and Recreation. This data layer, Timber eNVC, represents risk integrated across all Timber sub-HVRAs. The Timber HVRA is intended to evaluate wildfire risk to commercial timber resources. We grouped sub-HVRAs based on three criteria: land manager, assumed management priority, and timber size class. Land managers included private, state, U.S. Forest Service, Bureau of Land Management and Tribal entities. Sub-HVRAs include:

1. Private, Non-industrial, QMD < 10"

2. Private, Non-industrial, QMD 10" - 20"

3. Private, Non-industrial, QMD > 20"

4. Private, Industrial, QMD < 10"

5. Private, Industrial, QMD 10" - 20"

6. Private, Industrial, QMD > 20"

7. Tribal, Active Management, QMD < 10"

8. Tribal, Active Management, QMD 10" - 20"

9. Tribal, Active Management, QMD > 20"

10. Tribal, Other Management, QMD < 10"

11. Tribal, Other Management, QMD 10" - 20"

12. Tribal, Other Management, QMD > 20"

13. U.S. Forest Service, Active Management, QMD < 10"

14. U.S. Forest Service, Active Management, QMD 10" - 20"

15. U.S. Forest Service, Active Management, QMD > 20"

16. U.S. Forest Service, Other Management, QMD < 10"

17. U.S. Forest Service, Other Management, QMD 10" - 20"

18. U.S. Forest Service, Other Management, QMD > 20"

19. BLM, Active Management, QMD < 10"

20. BLM, Active Management, QMD 10" - 20"

21. BLM, Active Management, QMD > 20"

22. BLM, Other Management, QMD < 10"

23. BLM, Other Management, QMD 10" - 20"

24. BLM, Other Management, QMD > 20"

25. State, QMD < 10"

26. State, QMD 10" - 20"

27. State, QMD > 20"

Methods for mapping the extent of each land manager’s timberlands are described in detail in chapter 4.3.5 of the PNW QWRA 2023 Methods Report. We used assumed management priority criteria to distinguish between lands where commercial timber management is the primary objective from those lands where commercial timber management is part of a multiple use strategy. Tribal Active Management, U.S. Forest Service Active Management, BLM Active Management and Private Industrial sub-HVRAs all represent timberlands where commercial timber management is assumed to be the primary management objective. Within all other Timber sub-HVRAs, commercial timber management is presumed to be one of several equally important management objectives. State and federal agencies made these designations on public land and used available data for tribally-managed lands. We mapped timber size class data using Quadratic Mean Diameter (QMD) from the most recent forest structure data available which approximates forest structure in 2021 (LEMMA, 2023a). We included fire regime group (FRG), along with timber size class, as a covariate to explain the response to fire. We gave all land managers equal relative importance, but within a land manger type about twice as much importance was placed on active management timberlands compared to timberlands with multiple, equally important management objectives. Additionally, within any sub-HVRA the most relative importance was assigned to the largest size class, and the least was assigned to the smallest size class.

Risk is estimated within the QWRA framework by integrating wildfire hazard with HVRA susceptibility (Scott et al., 2013). Risk is calculated for each pixel separately based on the fire hazard data for that pixel and based on which HVRAs are present. Fire impacts to each HVRA are characterized by the estimated change in value, a unitless approximation of whether the HVRA is beneficially or adversely affected by fire and to what magnitude. Accordingly, risk is expressed as net value change (NVC). Net value change is first calculated for all pixels across a sub-HVRA. The NVC for each HVRA is then calculated by summing the NVC of all its constituent sub-HVRAs. Positive values indicate that wildfire is likely to have beneficial impacts on the HVRA while negative values indicate that the net outcomes are likely to be adverse. Risk is calculated based on a very wide range of plausible weather conditions, much wider than the range under which we have typically experienced large fires in the past. The specific conditions under which a wildfire occurs will determine the outcomes. When interpreting QWRA risk results bear in mind that fire will not always be beneficial in areas with positive NVC values and likewise it may be possible to experience beneficial fire in areas with negative NVC values.

Primary Data Contact: Ian Rickert, Regional Fire Planner, Forest Service R6/R10, ian.rickert@usda.gov

Citations:

Scott, J.H., Thompson, M.P., Calkin, D.E., 2013. A wildfire risk assessment framework for land and resource management (No. RMRS-GTR-315). U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Ft. Collins, CO. https://doi.org/10.2737/RMRS-GTR-315

Finney, M.A., McHugh, C.W., Grenfell, I.C., Riley, K.L., Short, K.C., 2011. A simulation of probabilistic wildfire risk components for the continental United States. Stoch Environ Res Risk Assess 25, 973–1000. https://doi.org/10.1007/s00477-011-0462-z