Term Papers due on Tuesday

1. Term Papers due on Tuesday Please turn in a hard copy plus your draft paper with my comments Tuesday: Review for Final

2. Fire Managementin the Wildland-Urban Interface(WUI)

3. Key Topics • What is the WUI? • Trends in WUI fire disasters • Fire policies affecting the WUI • Three approaches to protecting homes in the WUI: • Fire suppression • Fuel treatments • Creating defensable space (home ignition zone) • Exercise: preventing fire in the home ignition zone

4. Wildland-Urban InterfaceDefinition? • Wildland: • Area in which development is essentially non-existent, except for roads, railroads, pwerlines, etc., and any structures are widely scattered. • WUI • Zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels (NWFCG 2006) • An area where a wildland fire can potentially ignite homes

5. Since 1970: • >15,000 homes lost to wildfires • Suppression costs >$25 billion • Insurance costs >$10 billion

6. Broad scale national assessment of wildland fire risk

10. Trends in WUI fire disasters • 1870-1920: massive wildfires across millions of acres destroyed towns and caused thousands of fatalities (WI, MI, MN, ID, MT) – greater destruction of lives and property than past 50 yr. • Since 1985 – wildfires in the WUI recognized as a major problem • Policies: National Fire Plan (2000), Federal Wildland Fire management Policy (2001), Healthy forests Restoration Act (2003), Firewise program • Focus on increasing suppression efforts in WUI • Vast amounts of money spent (funds often exhausted)

11. Trends in WUI fire disasters • Despite recent emphasis on “fire use”, many more wildland fires are suppressed compared to those allowed to burn: • 1998-2007: ~80,000 wildland fires suppressed, vs. 327 designated as desirable prescribed fires • Suggests that the “fire exclusion paradigm” still continues. • In many ecosystems, resulted in changes in vegetation fuel structures and fuel accumulation, leading to more high intensity fires.

12. What is a “WUI fire Disaster”? • Only occurs when homes ignite during wildfire, otherwise problem doesn’t exist • Wildland fire suppression operations successfully control 97-99% of wildfires at initial attack. • Structure firefighters usually limit a fire to a single structure and prevent spreading. • Only during extreme wildfire conditions do numerous houses ignite and burn simultaneously – overwhelm efforts • Extreme fire behavior conditions account for 1-3% of wildfires that escape initial attack.

13. WUI fire disaster conditions

14. Can more suppression efforts prevent WUI fire disasters? • Under extreme weather conditions and fire behavior, suppression efforts are usually overwhelmed. • This is especially the case when multiple houses burn simultaneously under extreme fire conditions.

15. Can fuel treatments prevent WUI fire disasters? • Objective 1: Make wildlands “fire-proof” • Not possible for fire-dependent ecosystems • Objective 2: Facilitate suppression • = “The wildland fire paradox” • Fire suppression more effective, but the problem becomes worse • Less area burned in the short run, but more area burned under extreme conditions, when suppression is ineffective.

16. Can fuel treatments prevent WUI fire disasters? • Objective 3: Create conditions in which fire can occur without devastating consequences • Allow fires to burn without need for suppression • Will usually need to include the “home ignition zone” • Objective 4: Ecosystem restoration • Some ecosystem restoration treatments reduce fuel hazard, but not all fuel treatments restore ecosystems • Depends on to what extent they emulate historical conditions: what forests should we prioritize & why? • Examples: ponderosa pine, mixed conifer, drier Douglas-fir forests

17. Arizona

18. Montana

19. Principles of restoring fire regimes to dry forests with fire hazard reduction treatments

20. Fuelbreak in Wenatchee, WA

21. Fuel treatment area (removed surface & ladder fuels) - Megram Fire, CA

22. Fuel treatment: thinning & prescribed burning (Cone Fire, CA)

23. Home Ignitability & Survival: Can creating defensible space in the ignition zone prevent WUI fire disasters?

24. Preventing Disaster: Home Ignitability in the WUI (Cohen 1998) • 3 Approaches to determining ignitability and the ignition zone: • Modeling • Fire experiments • Case studies • TTYP – Explain for your case: 1) how the study was conducted? 2) what were the results? 3) what are the implications for preventing WUI fire disasters?

25. Fire experiments – wood ignition Exterior plywood (not treated) Heat flux sensors Repeated burns: 10 m 20 m 30 m 10m: scorched, no ignition 20m: lightly scorched 30m: not affected

26. SIAM: Structure Ignition Assessment Model • Ignition time: • - Heat flux • Distance • * Wildfire burn • Duration = 50-70 sec • Overestimates radiant heat flux - Extreme case scenario • Black-body radiating flame front (maximum heat transfer) • - Wildfires = variable heat

30. 20 homes destroyed under tree canopy

33. Case Studies • Bel Air fire (484 homes destroyed, 1973) • Painted Cave fire (479 homes destroyed, 1994) • Los Alamos (200 homes destroyed, 2000) • 90% survival of homes with vegetation clearance 10-20 m • Homes with nonflammable roots: 70% survival rate (vs. 19 % for flammable roofs)

34. Investigation of Cerro Grande Fire: Los Alamos (2000) • 200 homes totally destroyed or irreparably damaged • Fire suppression – saved some homes • High ignitability of most homes • Fires spread quickly • Simultaneous house fires • Overwhelmed suppression forces

35. Lake Arrowhead, CA – Oct. 22, 2007(homes continued to ignite and burn after wildfire intensity slowed)

36. Can creating defensible space in the ignition zone prevent WUI fire disasters? • The evidence: homes burn even when fire behavior in nearby forests is not extreme • A home’s ignition potential determined by: • Characteristics of its exterior materials & design • Response to burning objects within 100 feet • Response to firebrands • Combustion occurs by two principal ways: • Flames (radiation & convection heating) • Firebrand ignitions

37. Home can ignite • from 2 sources: • Directly from flames • Firebrands on house • *** Defensible space***

38. TTYP: Reducing fire risk in the WUI • You just bought a new home in the mountains of New Mexico, in the heart of ponderosa pine country (see photo on the wall). Make a list of all the actions that you plan to take in order to reduce the risk of fire to your new home. Separate your list into those actions that will reduce home ignitability, and those that will increase the amount of defensible space.

39. Common home situation in Los Alamos residential areas

40. The Firewise Communities/USA project provides citizens with the knowledge necessary to maintain an acceptable level of fire readiness, while ensuring firefighters that they can use equipment more efficiently during a wildland fire emergency. • The program draws on a community's spirit, its resolve, and its willingness to take responsibility for its ignition potential. • Enlist a wildland/urban interface specialist to complete a community assessment and create a plan that identifies agreed-upon achievable solutions to be implemented by the community. • Sponsor a local Firewise Task Force Committee which maintains the Firewise Community/USA program and tracks its progress or status.

41. FireWise Communities • What are some actions that communities can accomplish better than individual homeowners to reduce the risk of fire in the WUI?