Fire Hazard Severity Zoning (FHSZ) DRAFT MAP REVIEW and VALIDATION

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Fire Hazard Severity Zoning(FHSZ)DRAFT MAP
REVIEW and VALIDATION

• --Dave Sapsis
• dave.sapsis_at_fire.ca.gov

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Definitions
FHSZ 1985 v.4

• Hazard physical conditions that can cause
  damage
• Risk expected damage
• Fire Hazard (burn probability) x (fire behavior)

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Definitions (cont.)
FHSZ 1985 v.4

• Fire Hazard Severity Zones
• represent areas of variable size ranging from 20
  acres in urbanized areas to at least 200 acres in
  wildland areas, with relatively homogeneous
  characteristics regarding expected burn
  probability and potential fire behavior
  attributes based on climax fuel conditions over a
  30-50 year time horizon.

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Model Methods

• Statewide (100 M acres)
• Uniform data and techniques applied everywhere
• No jurisdiction influence on zones

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Model Structure

• Two Steps
• 1. Zoning
• Wildlands
• Developed/urban
• 2. Scoring

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Create Wild Land and Urban Zones
S T A R T
Torching Tree surface
Flame Score
Slope (0-20, 20)
Convert to Vector and Eliminate zones less than
200 acres
Flame Score by Zone (Flame_score_p)
Score Urban Zones
Score Wild Land Zones
Flame Class
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(No Transcript)
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Wildland Zoning

• Aggregated on slope and vegetation (200 ac)
• Slope lt or gt 20
• 5 principal Life Forms
• Grass, brushlands woodlands, conifer, conifer
  woodland

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Wildland Scoring

• Individual cells are scored based on expected
  chance of burning and the potential fire behavior
  for that site (including reception of firebrands)

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Wildland Scoring

• Scores are then averaged over the zone

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Wildland Scoring

• Zones are classified into three ranks Moderate,
  High, and Very High

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Developed Area Hazard

• Created in conjunction with UC Berkeley Center
  for Forestry
• Combination of Veg mapping, Density derived from
  census, and blocks of small parcels

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Developed Zoning

• Using 2006 parcel data
• Clusters of 20 acre minimum, with average maximum
  parcel size 1-1.5 ac.

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Developed Hazards

• Footprint aggregated from parcels, minimum size
  20 ac
• Wildland inholdings inside footprint must be gt20
  ac

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Developed Scoring

• Urban Burnability
• Footprint mapped for vegetation/fuel density
  (2005/06 TM imagery)
• Vegetation density used as measure of burnability
  or penetrability to wildland fire

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Developed Scoring

• FHSZ ranks within the footprint are a function
  of
• adjacent wildland score
• firebrand reception
• vegetation density

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Maps fixed to parcels
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FHSZ 2006

• Add developed FHSZ to wildland FHSZ to create
  seamless map
• SRA non-ranked zones are recoded to Moderate
• Zone edges snapped to parcels
• 5 ac parcels are not split
• SRA window defines FHSZ
• LRA window defines areas for Bates recommendations

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Deliverable products SRA - FHSZ
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Deliverable products LRA VHFHSZ (classified)
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Rollout/Implementation Process

• Policy committee under SFM/Fire Protection
• Authority for SRA hazard zones with Director of
  CDF
• LRA hazard zones adopted through hearings and
  local agency authority.
• Exploring webGIS for data/map delivery

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General Project Information

• http//frap.cdf.ca.gov/projects/hazard/fhz.html
• Includes link to draft maps for download
• Review Guidelines
• Comprehensive methods slideshow

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GIS review demonstration
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WUI Building Code Info

• http//osfm.fire.ca.gov/UWIBS.html