Hazards, Vulnerability, and Mitigation SubCommittee

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Hazards, Vulnerability, and Mitigation
Sub-Committee
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Massachusetts Statewide Risk Assessment

• An overview of the type and location of all
  natural hazards, including historical occurrences
  and probability of future occurrence
• An overview and analysis of the states
  vulnerability to the hazards identified by
  jurisdiction
• An overview and analysis of the vulnerability of
  state facilities to the hazards identified
• An estimate of potential losses by jurisdiction
• An estimate of potential losses to state owned
  facilities

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Identifying Natural Hazards

• Massachusetts State Hazard Mitigation Plans risk
  assessment, natural hazards have been grouped in
  the following categories  
• Flood Related Hazards heavy rain, dam failure,
  ice jams, coastal storms, and coastal erosion
• Atmospheric Related Hazards high winds,
  hurricanes, tornados, Noreasters, and severe
  thunderstorms
• Winter Related Hazards heavy snow, ice storms,
  and blizzard 
• Geologic Hazards earthquakes, landslides, and
  tsunami 
• Other Natural Hazards wildfire, conflagrations
  (major urban fires), drought, and extreme
  temperatures

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Flood Related Hazards

• Inland or Riverine Flooding
• Ice Jams
• Coastal Storms

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Inland or Riverine Flooding

• Riverine or inland flooding can be caused by a
  number of factors, heavy rain, snowmelt,
  ice-jams, dam-breaks, and more.
• Floods are among the most frequent and costly
  natural disasters
• The annual rainfall approximately 48 inches.
• 439 State owned structures in a SFHA.

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The 100 Year Flood

• The flood that has a 1 chance of occurring or
  being exceed in any given year.
• A structure located within a Special Flood Hazard
  Area (SFHA) shown on an NFIP map has a 26 percent
  chance of suffering flood damage during the term
  of a 30-year mortgage.
• FEMA produces Flood Insurance Rate Maps (FIRMs)
  which depict SFHA, the areas subject to
  inundation from the 1 annual chance flood  
• 1978-2008 gt26,000 claims totaling close to
  gt279,000,000

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Ice Jams

• A freeze up jam forms in the early winter as ice
  formation begins. This type of jam can act as a
  dam and begin to back up the flowing water behind
  it.
• A break up jam forms as a result of the breakup
  of ice cover, causing large pieces of ice to move
  downstream potentially acting as a dam, impacting
  culverts and bridge abutments.
• More than 200 reported ice jams in Massachusetts
  since 1910.
• North Central Massachusetts, averages at least
  one ice jam per year.

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Freeze Up Ice Jam Athol MA, 2004
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Coastal Storms

• Coastal storms are an intricate combination of
  events that impact a coastal area.
• A coastal storm can occur any time of the year
  and at varying levels of severity.
• Hurricane Bob and the 1991 October noreaster
  caused 174 million in uninsured and NFIP claims.
  

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Atmospheric Related Hazards

• High winds
• Hurricanes and tropical storms
• Thunderstorms
• Tornados
• Nor'easters

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Hurricanes and Tropical Storms

• An intense tropical weather system with a
  well-defined surface circulation and a maximum
  sustained winds of 75-mph or higher.
• Hurricane season from June 1 to November 30.
• Between 1851 and 2004 42 storms have made
  landfall in MA.

Massachusetts Hurricane and TS Landfalls
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Thunderstorms

• An atmospheric storm which can produce gusting
  winds, excessive rainfall amounts, hail, winds
  gusting, and/or tornados.
• Average duration 30 minutes  
• Recent disaster activity, in 1998 a thunderstorm
  caused more than 7 million in damage
  (FEMA-1224-DR-MA).
• The entire state of Massachusetts is susceptible
  to thunderstorms and severe storms.  

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Tornados

• A violently rotating column of air that extends
  from the base of a thunderstorm to the ground.
• Tornados are the most violent of all atmospheric
  storms.
• Based on past events, the area at greatest risk
  for a tornado touchdown central to northeastern
  Massachusetts.
• Most destructive tornado in New England history
  was the Worcester tornado of June 9, 1953, F-4

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Noreaster

• Large counter-clockwise wind circulation around a
  low pressure center.  
• Damages flooding, wind damage, storm surge and
  erosion
• Average frequency of 1 or 2 per year
• Average duration can be from 12 hours to 3 days.

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Winter Related Hazards

• Heavy Snow
• Ice storms
• Blizzards

Photo Credit Martin Greene
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Heavy Snow

• Blowing Snow Squalls

• Average annual Snowfall
• Blue Hills, MA 61.0 Inches
• Boston, MA 43.3 Inches
• Worcester, MA 69.1 Inches

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Other Natural Hazards

• Drought
• Major Urban Fires
• Wildfire
• Extreme temperatures

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Geologic Hazards

• Earthquake 
• Landslide
• Tsunamis 

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Earthquake

• The last major earthquake to affect Massachusetts
  was more than 200 years ago in 1755 with an
  estimated magnitude of 6.0. The epicenter was
  located off the coast of Cape Ann, north of
  Boston.

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Questions??