Module 2.) Levels of Assessment Flashcards
categorization of the breadth and depth of analysis used in an assessment
Level(s) of assessment
a visual assessment from a specified perspective such as a foot, vehicle, or aerial (airborne) patrol of an individual tree or a population of trees near specified targets to identify conditions or obvious defects of concern.
Limited visual assessment (level 1)
a defined set, group, or collection of trees.
Tree population
a limited visual inspection, usually from one side of the tree, performed as the tree risk assessor walks by the tree(s)
Walk-by (assessment)
limited visual inspection from only one side of the tree, performed from a slow-moving vehicle. Also may be called a windshield assessment.
Drive-by (assessment)
overflights of a utility right-of-way, large areas, or individual trees in a defined area to record the location of trees that are likely to fail and cause harm.
Aerial patrol
a remote sensing method that uses laser technology to measure tree size and location in relation to the target of concern.
LiDAR
Light Detection and Ranging
detailed visual inspection of a tree and surrounding site that may include the use of simple tools. It requires that a tree risk assessor inspect completely around the tree trunk looking at the visible aboveground roots, trunk, branches, and site.
Basic assessment (level 2)
a measuring tape scaled such that when it encircles a tree trunk, the width can be read directly.
Diameter tape
instrument used for measuring the height of a tree or other structure.
Clinometer
a broad headed hammer made of wood, plastic, or resin used for “sounding” a tree.
Mallet
a stiff, small-diameter rod, stick, or wire that is inserted into a cavity or crack to estimate its size or depth.
Probe
an assessment performed to provide detailed information about specific tree parts, defects, targets, or site conditions. Specialized equipment, data collection and analysis, and/or expertise are usually required.
Advanced assessment (level 3)
inspection of the upper tree parts not readily accessed from the ground; typically done by climbing or from a lift.
Aerial inspection
an instrument or tool developed to detect decay in tree parts.
Decay-detection device
degradation of the ability to withstand mechanical stress.
Strength loss
a device consisting of a specialized micro-drill bit that drills into trees and graphs resistance to penetration; used to detect internal differences in the wood, such as decay.
Resistance-recording drill
a process of measuring wood density, or other mechanical properties, using an instrument that transmits, receives, and records the velocity of sound or electric waves through wood.
Sonic assessment
use of multiple sensors placed around a trunk of limb to record sound or magnetic waves traveling through the wood, with measurements resulting in a picture of internal density characteristics. Typically used in arboriculture to measure the extent of decay in trees.
Tomography
roots at the base that help support the tree and equalize mechanical stress.
Buttress roots
process of removing soil to expose and assess the root collar (root crown) of a tree.
Root collar excavation (RCX)
a nondestructive device that uses radar pulses to image the subsurface.
Ground-penetrating radar
in advanced tree risk assessment, pulling tests to measure or observe the amount of inclination and/or deformation to assess stability.
Load testing
a load test that involves installing a line in a tree, and the pulling and releasing the line several times to move the tree or branch. Most commonly used in a pre-work inspection, but can be used as part of an advanced tree risk assessment.
Hand pull test
in advanced tree risk assessment, a load test that measures outermost fiber strain in the stem or branches, and/or inclination at the root flare, in response to a controlled pull.
Static pull test
True/False
If an assessor determines that further inspection is required, s/he should go ahead and inspect the tree at a more detailed level of assessment.
False
True/False
A drive-by assessment may be a reasonable method to quickly assess immediate risks in a large population of trees.
True
True/False
Tools used for a Level 2 assessment might include diameter tape, a trowel, and a mallet.
True
True/False
When assessing street trees, the targets may be consistent along the entire street and the likelihood of impact and consequences of failure may be held constant.
True
True/False
If all techniques in a Level 3 assessment were sued, an assessor could predict with certainty when the tree would fail.
False
A __________ is a limited visual inspection of one or more sides of the tree, performed as the inspector passes a tree on foot.
walk-by assessment
A simple tool used for a basic assessment might include a __________, which can help determine the presence of decay when inserted into a cavity.
probe
A __________ test can be performed with a light-duty line to look for signs of excessive movement in the branches, or instability in the trunk. A __________ test measures fiber strain in the stem and branches, and inclination in the root flare.
hand pull
static pull
One example of a level __________ assessment is sonic tomography, where sound waves traveling through wood are used to create a tomogram.
three
The amount and extent of internal decay can be estimated by
A) observing response growth and compartmentalization
B) sounding and/or probing
C) performing advanced assessment techniques
D) all of the above
D) all of the above
The reason three levels of assessment are defined is
A) to provide one level each for municipal, utility, and commercial applications
B) because arborists must look above ground, below ground, and inside of a tree
C) not all trees or situations require the same depth and breadth of assessment
D) all of the above
C) not all trees or situations require the same depth and breadth of assessment
Which of the following is NOT part of the Level 1 assessment process?
A) assess the tree(s) of concern from the defined perspective (e.g., walk-by, drive-by)
B) record locations of trees that meet the defined criteria (e.g., significant defects or other conditions of concern)
C) sound and/or probe trees with obvious cavities to determine the extent of decay
D) identify trees needing a higher level of assessment and/or prompt action
C) sound and/or probe trees with obvious cavities to determine the extent of decay
A Level 2 assessment requires the assessor to
A) inspect completely around the tree
B) inspect the visible buttress roots
C) inspect the trunk and branches
D) all of the above
D) all of the above
Which of the following tools are commonly used in a Level 2 assessment, but are not required?
A) air excavation device
B) mallet and probe
C) decay detection device
D) inclinometer
B) mallet and probe
Level 3 assessments are generally more time intensive and more expensive than Level 2 assessments because
A) they require specialized equipment, data collection and analysis, and/or expertise
B) the potential consequences of tree failure are significantly higher than normal
C) they involve trees with the highest likelihood of failure
D) all of the above
A) they require specialized equipment, data collection and analysis, and/or expertise
Level 3 assessments are typically performed
A) routinely, after most limited visual assessments, to follow up on trees of concern
B) in conjunction with or after a basic assessment, if an assessor needs additional information to assess the risk, and if the tree owner/manager approves the additional service
C) whenever internal decay is suspected, to provide additional information about the extent and location of the decay
D) whenever more information is required than can be determined from a basic assessment, regardless of the level of risk
B) in conjunction with or after a basic assessment, if an assessor needs additional information to assess the risk, and if the tree owner/manager approves the additional service
