Debris Management in Alberta Fuel Management Workshop October 2003

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Debris Management in AlbertaFuel Management
WorkshopOctober 2003

• Greg Baxter Researcher, WFORGFERIC Western
  Division

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Background

• Debris management has been an issue since the
  1890s when the first tree was harvested (P.
  Murphy)
• The Dominion Timber Regulations were amended in
  1898 to include requirements for disposal of
  logging debris and to require timber operators to
  share the costs of forest protection.
• This problem has been studied a number of times
  this being the most recent.

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Past Work (examples)

• Bennett, W.D. 1960. The reduction of forest fire
  hazard created by logging slash.
• Literature review
• Kiil, A.D. 1964 moisture content of slash
  fuels.
• Also moisture content study five years after
  logging (1968)
• 1972 Task Force report for the reduction of slash
  hazard on logging operations (Benson, J.E)
• (Hazard rating system and wildfires from slash
  have not caused us any problems to date.

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Past Work

• Little quantitative data collected on fire
  behaviour (intensities and spread mechanisms) of
  debris and piles involved in wildfires.

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Current Issues

• Provincial legislation states that slash hazard
  reduction is required within 24 months
  (primarily by burning).
• Some Companies would rather spread debris or pile
  and not burn mostly due to liability concerns.
• Are there alternatives?
• Can we learn from the fire history or case
  studies of fire behaviour? Are there species
  differences?

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Recent High Profile Fires Involving Debris

• 1998 Slave Lake Fires
• 2000 Cherry Hill Fire
• 2001 Chisholm Fire
• 2002 House River Fire
• 2003 Lost Creek Fire

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Observed Problematic Fire Behaviour

• Spotting (pile-to-pile and pile to forest).
• Pile-to-pile spread (radiation or direct flame
  contact).
• Grass fire behaviour combined with heavy fuel
  loads.
• Overnight fire spread.
• Difficult/expensive to extinguish.

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History of Debris Fires

• Debris fires extracted from fire history database
  for the period 1961- 2000. Sorted by size, month,
  cost, cause and location.
• Since 1961, debris has been involved in more than
  3,200 fires as a primary or secondary fuel.
• Lightning and land clearing activities are major
  sources of ignition.

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Total Wildland Fires by Time Period
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Debris Fires by Time Period
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Debris fires 1961-2000

• Province wide distribution
• West-central weighting
• 3224 fires (80/year or 10 of all fires)

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Fires by Month
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Ignition

• Two primary causes
• Lightning (36) June-August.
• Land clearing including forestry, transportation
  and private landowners. (30) (May-June).
• Other causes include man accident (13),
  equipment (5) and vandalism (4).

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Lightning Fires (34)

• Province wide distribution with a grouping in the
  west-central region, the lightning belt in
  province.
• 1134 fires

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Industry Fires

• Includes
• Oil and Gas
• Forestry
• Other Industry
• Transportation
• 675 fires

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Winter Fires

• Almost all burning occurs during winter even
  with snow these can be problematic
• Wind events can cause winter burns to escape.
  There are many examples of Chinooks causing
  escapes resulting in fires of significant costs.
• Holdover fires. Fires burned during winter and
  believed out, can re-surface and escape in the
  spring. This problem appears to be increasing.

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Over-wintering firesFires ignited during winter
that re-surface after April 1st.
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Regional Trendsand Regional Solutions.

• The fire history revealed the number number of
  fires, causes and stand types vary in the
  province. Four regions stand out
• SE Slopes Chinooks, steep slopes
• East-central aspen debris
• West-central lightning frequency
• North organic soils, lightning.

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Regions

• SE Slopes
• East-central
• West-central
• North

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Southeast Slopes

• Abundant debris from decadent stands, steep
  slopes.
• Fewer debris fires than other regions but
  large, intense, expensive fires have recently
  occurred.
• Winter burning is a concern unreliable
  snowpacks and strong, unpredictable winds create
  problematic conditions.
• Better knowledge of Chinooks required.

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Southeast SlopesPotential Treatments

• Must burn debris problematic in wildfires.
• 1 in 4 piles can be left as wildlife piles (based
  on fire history).
• Development of an east-slope scale Chinook Risk
  map.
• Use of Simple burn plans.

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East-central Region

• Characterized by large stand replacing fires.
• Aspen is a harvested species.
• Little research of fire behaviour in aspen
  debris.
• Aspen piles have recently contributed to
  problematic fire behaviour.

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East-central RegionPotential Treatments

• Increase distance between aspen piles. Size
  limits to the piles.
• Eliminate all coniferous debris.
• Spreading aspen debris may be a potential
  solution.
• Debris-free distance around values-at-risk (using
  WTA).

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West-central Region

• Significantly more fires than any other regions
  Why?
• Region lies in THE lightning belt.
• Heavy industry use over along time period.
• Influenced by Chinook in western portion.
• Increase in over-winter fires

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West-central RegionPotential Solutions

• Lightning location study.
• Lightning mitigation techniques (are there any?).
• One pile/4 hectares for wildlife piles.
• Development of infrared scanning standards
  (includes equipment).

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Northern Region

• Aspen also harvested.
• Highest percentage of lightning caused debris
  fires.
• Generally stable winter burning conditions (few
  over-winter fires).
• Ground fires are a concern.

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Northern RegionSolutions

• Soils map.
• Aspen wildlife piles.
• Lightning mitigation techniques.
• Pile burn checklist for industry and
  land-owners.
• Combine FWI snow-on-ground data to develop a
  risk chart for burning.

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Existing Fire Behaviour Research(available on web)

• Some research has occurred in the following
  areas
• Pile shape
• Debris loading hazards - quantity
• Debris age and hazard needle retention
• Moisture Content studies (age)
• Aspen fire behaviour (limited)
• Spotting models

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Knowledge Gaps

• Document fire behaviour in both conifer and aspen
  debris using case studies and experimental
  debris fires.
• Determine a scientifically based pile-to-pile
  distance to mitigate influence of debris piles
  during wildfires that includes
• Spread via spotting
• Spread from radiation
• Spread by direct contact

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Knowledge Gaps (cond)

• Debris Arrangement
• Are there debris arrangements that may decrease
  fire intensity? I.e.,
• Spreading
• Pile size and shape
• Spatial distribution
• Species specific guidelines

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Mechanised Solutions

• Slash bundler - cogen
• Chipping
• Mulching The Bull
• May be used in targeted areas, but at this time
  uneconomic to treat all blocks.