HomeMy WebLinkAboutTR_ISA_Basic_Tree_Risk_Assessment_Form — Trunk —
— Crown and Branches —
— Roots and Root Collar —
Unbalanced crown LCR ______%
Dead twigs/branches ____% overall Max. dia. ______
Broken/Hangers Number __________ Max. dia. ______
Over-extended branches
Pruning history
Crown cleaned
Reduced
Flush cuts
Thinned
Topped
Other
Raised
Lion-tailed
Cracks ___________________________________ Lightning damage
Codominant __________________________________ Included bark
Weak attachments ___________________ Cavity/Nest hole ____% circ.
Previous branch failures _______________ Similar branches present
Dead/Missing bark Cankers/Galls/Burls Sapwood damage/decay
Conks Heartwood decay ________________________
Response growth
Collar buried/Not visible Depth________ Stem girdling
Dead Decay Conks/Mushrooms
Ooze Cavity _____% circ.
Cracks Cut/Damaged roots Distance from trunk _______
Root plate lifting Soil weakness
Response growth
Main concern(s)
Load on defect N/A Minor Moderate Significant
Dead/Missing bark Abnormal bark texture/color
Codominant stems Included bark Cracks
Sapwood damage/decay Cankers/Galls/Burls Sap ooze
Lightning damage Heartwood decay Conks/Mushrooms
Cavity/Nest hole _____ % circ. Depth _______ Poor taper
Lean _____° Corrected? ________________________________
Response growth
Main concern(s)
Load on defect N/A Minor Moderate Significant
Client _______________________________________________________________ Date___________________ Time_________________
Address/Tree location _________________________________________________________ Tree no.____________ Sheet _____ of _____
Tree species _________________________________________ dbh_____________ Height ___________ Crown spread dia. ____________
Assessor(s) __________________________________________ Time frame_____________ Tools used______________________________
Target Assessment
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Target description
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History of failures _____________________________________________________________ Topography Flat Slope _________% Aspect _____
Site changes None Grade change Site clearing Changed soil hydrology Root cuts Describe _____________________________________
Soil conditions Limited volume Saturated Shallow Compacted Pavement over roots ______% Describe __________________________
Prevailing wind direction______ Common weather Strong winds Ice Snow Heavy rain Describe______________________________
Tree Health and Species Profile
Vigor Low Normal High Foliage None (seasonal) None (dead) Normal _____% Chlorotic _____% Necrotic _____%
Pests_____________________________________________________ Abiotic ________________________________________________________
Species failure profile Branches Trunk Roots Describe ____________________________________________________________________
Load Factors
Wind exposure Protected Partial Full Wind funneling ________________________ Relative crown size Small Medium Large
Crown density Sparse Normal Dense Interior branches Few Normal Dense Vines/Mistletoe/Moss _____________________
Recent or planned change in load factors _________________________________________________________________________________________
Tree Defects and Conditions Affecting the Likelihood of Failure
Occupancy rate1–rare 2 – occasional 3 – frequent 4 – constant
Likelihood of failureLikelihood of failure
Basic Tree Risk Assessment Form
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Site Factors
Target zone
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Main concern(s)
Load on defect N/A Minor Moderate Significant
Likelihood of failure Improbable Possible Probable Imminent
Improbable Possible Probable Imminent Improbable Possible Probable Imminent
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Matrix 1. Likelihood matrix.
Likelihood
of Failure
Likelihood of Impacting Target
Very low Low Medium High
Imminent Unlikely Somewhat likely Likely Very likely
Probable Unlikely Unlikely Somewhat likely Likely
Possible Unlikely Unlikely Unlikely Somewhat likely
Improbable Unlikely Unlikely Unlikely Unlikely
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Target
protection
Conditions
of concern
Failure Impact Failure & Impact
(from Matrix 1)
Likelihood
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Consequences
Risk rating
of part
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Matrix 2)Tree part
Likelihood of
Failure & Impact
Consequences of Failure
N e g l i g i b l e Minor Significant Severe
Very likely Low Moderate High Extreme
Likely Low Moderate High High
Somewhat likely Low Low Moderate Moderate
Unlikely Low Low Low Low
Data Final Preliminary Advanced assessment needed No Yes-Type/Reason ________________________________________________
Inspection limitations None Visibility Access Vines Root collar buried Describe ___________________________________________
Notes, explanations, descriptions
Mitigation options _____________________________________________________________________ Residual risk ________
____________________________________________________________________________________ Residual risk ________
____________________________________________________________________________________ Residual risk ________
____________________________________________________________________________________ Residual risk ________
Overall tree risk rating Low Moderate High Extreme Work priority 1 2 3 4
Overall residual risk Low Moderate High Extreme Recommended inspection interval __________________
This datasheet was produced by the International Society of Arboriculture (ISA) and is intended for use by Tree Risk Assessment Qualified (TRAQ) arborists – 2013
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Matrix 2. Risk rating matrix.
Risk Categorization
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