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Impact of Storms in the Northeast : Weather and Trees
Richard J. Hauer, Ph.D.College of Natural Resources
University of Wisconsin-Stevens Point
Storm Preparedness and Response:Lessons from the Past, Techniques and Tools for the Future
September 26, 2006 Providence, Rhode IslandSponsored by the Rhode Island DEM and the USDA Forest Service
The Not So Beauty of Storms
Safety CleanupRepair
Overtime
Storm Response … A Three Act Play
Act I: The Problem (Impact of Storms)
Act II: The Response (DPRR Cycle)
Act III: The Outcome (M & M)
http://www.uwsp.edu/cnr/faculty/hauer/index.htm
or Google Hauer UWSP
Bio …. Logical in the Urban Forest
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Predictable and Preventable Act One:Weather, Storms and the Urban Forest
• Types– Floods– Moisture Stress/Drought– Ice Storms– Tornadoes– Lightening– Hurricanes– Nor’easter– Straight-line Winds– Forest Fires
• When and how often?
Outcomes
Acute versus
Chronic
Short-term or Residual
Temperature
• Means and Extremes– Average High 82°– Average Low 20°– Highest Temp 104° (August 2, 1975)– Lowest Temp -25° (February 5, 1996)
• Hardiness and Heat Tolerance
Minnesota Tree Spade Planting January 10, 2003
Spruce Winter Desiccation, Planted the Previous Fall (Purplish Coloration) Frost Damage to Trees
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Moisture Stress and Drought• Moisture Stress:
– Plant response– Reduced growth and development
• Drought:– Meteorological definition– … period of abnormally dry weather sufficiently long
enough to cause a serious hydrologic imbalance in the affected area.
– … severity depends on the degree of moisture deficiency...duration... and to some extent the size of the area affected.
– … usually reserved for a time of moisture deficiency that is relatively extensive in time and space.
Species Response to Moisture Stress and/or Drought
Copyright © 2006, PRISM Group, Oregon State University, http://www.prismclimate.org Map created 09/21/2006.
Effects of Moisture Stress• Deficiency• Excess
• Physical damage– Snow– Ice– Fires
Hail
Direct and Indirect Effects of Hail
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Ice Storms
How Common
Ice Storm Development
1998 January Ice Storm inNE US andSE Canada
Flooding
Species and Duration
XSweetgumLiquidambar styracifluaXBlack walnutJuglans nigraXKentucky coffeetreeGymnocladus dioicus
XHoneylocustGleditsia triacanthosXWaterlocustGleditsia aquatica
XXgreen ashFraxinus pennsylvanicaXWhite ashFraxinus americana XHackberryCeltis occidentalis
XShagbark hickoryCarya ovata XBitternut hickoryCarya cordiformis
XWater hickoryCarya aquaticaXRiver birchBetula nigra XHazel alderAlnus rugosaXXSilver mapleAcer saccharinum
XRed mapleAcer rubrum XXBoxelderAcer negundo
Tolerant³Tolerant ²Tolerant¹NameSpecies
Intolerant4SomewhatVeryCommon
Some Flood Tolerance Ratings of Tree Species: Intolerant < 30 days, Intermediate 30 to 60 days, tolerant > 60 days
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What Caused This?Winds and Damage
• Sustained winds
• Gusts
• Damage Categories– Defects (decay, branch structure, roots)– Sound Trees (resistance to wind, force)
Fujita Scale
Trees debarked261–318incredibleF5
Forest trees uprooted and carried207–260devastatingF4
Most trees in forest uprooted158–206severeF3
Large trees broken or uprooted113–157significantF2
Trees broken or uprooted73–112moderateF1
Twigs/branches break, shallow rooted species uprooted
40–72lightF0
Tree Damage
Wind Speeds (mph)DamageCategory
Beaufort Wind Scale
64 - 7212Trees broken or uprooted55 - 6311
47 - 5410Twigs break39 - 469Whole trees in motion32 - 388Large branches in motion25 - 317Small trees in leaf begin to sway19 - 246Small branches in motion13 - 185Leaves & small twigs in constant motion8 - 124Leaves rustle4 - 73
1 - 32Calm0 - 11Outcome
Wind Speed
Beaufort Number
Spruce (not a palm) Tree
in Crookston, MNNor’easter
• Forces– Wind– Snow
• Tree Damage– Many trees were blown down – More latter killed from seawater blown inland
• Ice The Groundhog Day gale (1976)– Maximum sustained winds of 102 mph– Equal to a Category 2 hurricane (gusts to 116 mph)
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Tornados
• Top 5 states (mean # per year, 1950–2004): Texas (134), Oklahoma (58), Kansas (56), Florida (51), Nebraska (43)
States with lowest incidence of tornadoes (total number, 1950–2004): Alaska (2), Rhode Island (9), Hawaii (31), Vermont (37), Oregon (87)
March 29, 1999 St. Peter Storm
Recovery from St. Peter Tornado What are the Safety Issues
Why is Safety Important?
Opps
Act II
Storm Preparedness and Response
Richard J. Hauer, Ph.D.College of Natural Resources
University of Wisconsin-Stevens Point
Storm Preparedness and Response:Lessons from the Past, Techniques and Tools for the Future
September 26, 2006 Providence, Rhode IslandSponsored by the Rhode Island DEM and the USDA Forest Service
7
Storm Damage Preparedness
Now is not the time to start planning!
Now is the time for recovery and returning order
An Integrated Approach
What we Know From Tree Risk
Management:
1) Divide the community into tree risk zones
2) Tree failure is often
predictable and preventable
Historical Lessons Learned
84% of storm-damaged trees had pre-existingdefects that could have been predicted andprevented.
The Disaster Cycle1) Mitigation: activities that
reduce the effects of disasters
2) Preparedness: planning a response prior to a disaster
3) Response: activities during a disaster to minimize hazards in effective, efficient, and equitable ways
4) Recovery: returning to normal following a disaster
Disaster Cycle: Mitigation
• Tree Selection and Placement
• Tree Establishment
• Tree Maintenance
• Regular Tree Risk Assessment
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Disaster Cycle: Preparedness
• Staff Liaison/POC: know ICS; trained to access tree damage
• Tree Emergency Response Plan: guide before and after storm (prevention, clean-up, regulations, salvage/repair, replanting, mobilization agreements for people and equipment)
• Plan Coordination: assign responsibility, avoid conflicts
• Update Plan: periodic evaluation (annually), contracts, contacts, and changes
• Provide Training: what to do, who does it, when to do it
Disaster Cycle: Response
• Locate and Consult Emergency Plans, Debris Removal Plan, and Contact Lists
• Identify Live Electric Wires (in, on, or under trees)
• Implement Response Phase Triage– Response I – Debris clearance– Response II – Debris removal and disposal
Disaster Cycle: Response:Phase I – Debris clearance
• Clear priority traffic lanes and culverts
• Push debris to the side
• Clear at least one lane ASAP
• Clear major walkways
Disaster Cycle: Response:Phase II Debris removal and disposal• Establish routes and methods for clearing tree debris.
(hopefully set up before the disaster; if not, try adopting routes used for trash pickup or snow removal)
• Use staging areas if needed (malls, playgrounds, etc.), then clear those after things calm down.
• Debris removal typically most difficult tree disaster problem for communities and individuals.
• In general, removal of debris from public property is eligible for FEMA assistance when a Federal Disaster has been declared and when it constitutes an immediate threat to life, public safety, or improved property.
Disaster Cycle: Response:Communication
• Basic Point: Communication is critical to surviving disasters. If you do not actively manage information during tree emergencies, things have a way of quickly getting out of hand and complicating your work.
• Set up: clear communication channels among emergency agencies and personnel.
• Establish and publicize: a phone number and staff person for public contact.
• Media: Work with the media early and often.
• Deliver: important messages to the community
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Disaster Cycle: Recovery
• Tree by Tree Assessment for Hazards
• Prioritize Repair (tree data, location, other)
• Update Tree Inventory
• Continue to Keep Records for Assistance– keep track of date, personnel, job, equipment, location,
and hours.– Consult FEMA forms and requirements
(http://www.fema.gov)
Survey of Immediate Threats
• Determine Priority 1 Removal (e.g., uprooted, split in half, undermined)
• Determine Priority 1 Pruning (e.g., >= 2”hanging, broken, or cracked)
• Targets (e.g., building, sidewalk, electric wire, road, or other important structure)
• Hire professionals• Standards (ANSI A300) • Verify before you pay
Storm Damage Assessment Protocol
FEMA Reporting & ReimbursementFEMA recommends communities have an Emergency Operation Plan
FEMA reimburses:
Debris removal costs (estimate of ft3 of debris)
Tree removal costs (50% crown loss)
Hazard reduction pruning (only hazard limbs)
Act III
Mitigation: Minimizing Risk and Damage
Richard J. Hauer, Ph.D.College of Natural Resources
University of Wisconsin-Stevens Point
Storm Preparedness and Response:Lessons from the Past, Techniques and Tools for the Future
September 26, 2006 Providence, Rhode IslandSponsored by the Rhode Island DEM and the USDA Forest Service
10
Storm Damage PreventionStorm Damage Prevention
critical to public safety, similar in critical to public safety, similar in importance to other essential public importance to other essential public services such as:services such as:
Traffic light maintenance
Roadway construction & repair
Sewage disposal
Clean drinking water
Historical Lessons Learned
Storms will occur and the risk trees pose to the public safety are often very high.
11
Post Storm Surveys in Minnesota
84 % of damaged trees had pre-existing defects that were preventable and predictable.
Most common pre-existing defects:Decay
Weak branch unions
Codominant leaders
Stem girdling roots
Historical Lessons Learned
84 % of storm-damaged trees had pre-existingdefects that could have been predicted andprevented.
Storm Failure Triangle
Tree Condition and Defects
Loading Event
Site Characteristics
Failure Potential
Risk Management
Urban Forest Management
PreventionPlantingMaintenanceRemovalEmergency ResponseAdministration
Assessment
Correction
Defect Defect CategoriesCategories
Prioritizing Prioritizing ““Levels of RiskLevels of Risk””
• Some need “immediate” attention
• Some placed on the “back burner”
• Some regarded as “acceptable,” e.g.,
Pot Holes
Uneven Sidewalks
Bridges
12
A Systematic Approach is NecessaryA Systematic Approach is Necessary
To accurately assign levels of risk, managers need to be guided by a systematic approach:
•Observe
•Monitor
•Evaluate
•Prioritize
•Take Action
Predictable and Preventable
However, Many Potential Problems areHowever, Many Potential Problems are
Urban Forest Managers Must be Trained and Experienced in Risk Detection:
Levels of Risk Can be AssessedLevels of Risk Can be Assessed Monitor for Indicators:
• Decay
Monitor for Indicators:Monitor for Indicators:
• Poor Branch Attachments
Monitor for Indicators:Monitor for Indicators:
• Site condition changes, such as root loss
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Monitor for Indicators:Monitor for Indicators:
• Exposure to Wind Need Training and Experience toDetermine Best Treatment Options:
• Move the Target
• Treat the Tree
• Convert to Wildlife Tree
• Close the Site
• Remove the Tree
Urban Forest ManagersUrban Forest Managers
Treatment Options:
• Move the Target
Treatment Options:
• Treat the Tree
Treatment Options:
Convert to a “Wildlife Tree”[reduce the tree risk]
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Treatment Options:
Close the site[often not practical in urban settings]
Treatment Options:
• Remove the Tree
Design and Planning:• Minimize Utility Conflicts
Basal Pruning a
Hazardous Situation
Basal Pruning Gone Bad Design and Planning:
Provide adequate space
15
Design and Planning:
Species to Site Selection
Design and Planning:
Minimize Construction Damage
Design and Planning
When Streets are Widened and Improved, Tree Spaces Shrink:
Damaging Factors with Street and Sidewalk Repair
Street Reconstruction on Tree Survival• Five Percent Greater Mortality, 1989 Study
• No difference 2005 Study, Why?
Figure 1. Condtion rating of street trees subjected to construction damage during street, curb, and sidewalk repair and undamaged control trees. (Bars are Std. Error of Mean)
76.774.4
71.871.0
0
10
20
30
40
50
60
70
80
90
100
1989 2005
Cond
ition
Rat
ing
(Per
cent
)
Control Damaged
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Design and Planning:
Create complimentarymaintenance practices
Sign Damage to Trees (Tree Kiosk)
The End!