BMP - Utility Tree Risk Assessment - 28

may also be considered, but are usually difficult to assess without a higher
level of assessment. Site topography, including slope and aspect, are also relevant factors in some cases. These factors may increase likelihood of failure
during wind events.

Wind and Weather

Most tree failures occur when strong or erratic winds, rain, snow, or ice
loads exceed the tree's capacity to withstand the load. Wind speeds are
strongly affected by topography. In urban areas, wind speeds vary depending
on placement in the landscape; trees that are located on the leeward side of
taller buildings are exposed to slower wind speed than those along streets
through which wind is funneled by surrounding structures. Knowledge of
regional and local climate, wind and precipitation patterns, and observation
of specific site conditions are important in assessing the likelihood of
failure.
Some tree failures in normal wind speeds are associated with serious, uncorrected, or unmitigated structural defects or other conditions, alone or in
combination. However, many trees that fail under normal conditions do not
exhibit symptoms that would have been detectable during a Limited Visual
assessment.
When wind speeds exceed strong gale force, even defect-free trees and tree
parts can fail. When wind speeds reach hurricane force, failure of defect-free
trees can be widespread. Wind speed is variable; winds can be sustained, but
commonly occur in gusts that may exceed the reported, sustained wind
speed. Microbursts that produce exceptionally strong lateral wind shear
conditions can fail structurally sound, mature trees.
In some locations where strong winds are rare or infrequent, the wind speed
at which failures of structurally sound trees occur may be lower. Trees adapt
to their loads and, therefore, to the wind speeds that commonly occur in an
area. Trees with weak wood structure generally fail at lower speeds than
other species. It is common to find regional patterns of failure with key tree
species that should be considered during an assessment.
When evaluating wind loads during tree risk assessment, the assessor should
consider the normal range of wind and weather conditions for the region.
28



BMP - Utility Tree Risk Assessment

Table of Contents for the Digital Edition of BMP - Utility Tree Risk Assessment

Table of Contents
BMP - Utility Tree Risk Assessment - Cover1
BMP - Utility Tree Risk Assessment - Cover2
BMP - Utility Tree Risk Assessment - i
BMP - Utility Tree Risk Assessment - ii
BMP - Utility Tree Risk Assessment - Table of Contents
BMP - Utility Tree Risk Assessment - iv
BMP - Utility Tree Risk Assessment - v
BMP - Utility Tree Risk Assessment - vi
BMP - Utility Tree Risk Assessment - vii
BMP - Utility Tree Risk Assessment - viii
BMP - Utility Tree Risk Assessment - ix
BMP - Utility Tree Risk Assessment - x
BMP - Utility Tree Risk Assessment - xi
BMP - Utility Tree Risk Assessment - xii
BMP - Utility Tree Risk Assessment - 1
BMP - Utility Tree Risk Assessment - 2
BMP - Utility Tree Risk Assessment - 3
BMP - Utility Tree Risk Assessment - 4
BMP - Utility Tree Risk Assessment - 5
BMP - Utility Tree Risk Assessment - 6
BMP - Utility Tree Risk Assessment - 7
BMP - Utility Tree Risk Assessment - 8
BMP - Utility Tree Risk Assessment - 9
BMP - Utility Tree Risk Assessment - 10
BMP - Utility Tree Risk Assessment - 11
BMP - Utility Tree Risk Assessment - 12
BMP - Utility Tree Risk Assessment - 13
BMP - Utility Tree Risk Assessment - 14
BMP - Utility Tree Risk Assessment - 15
BMP - Utility Tree Risk Assessment - 16
BMP - Utility Tree Risk Assessment - 17
BMP - Utility Tree Risk Assessment - 18
BMP - Utility Tree Risk Assessment - 19
BMP - Utility Tree Risk Assessment - 20
BMP - Utility Tree Risk Assessment - 21
BMP - Utility Tree Risk Assessment - 22
BMP - Utility Tree Risk Assessment - 23
BMP - Utility Tree Risk Assessment - 24
BMP - Utility Tree Risk Assessment - 25
BMP - Utility Tree Risk Assessment - 26
BMP - Utility Tree Risk Assessment - 27
BMP - Utility Tree Risk Assessment - 28
BMP - Utility Tree Risk Assessment - 29
BMP - Utility Tree Risk Assessment - 30
BMP - Utility Tree Risk Assessment - 31
BMP - Utility Tree Risk Assessment - 32
BMP - Utility Tree Risk Assessment - 33
BMP - Utility Tree Risk Assessment - 34
BMP - Utility Tree Risk Assessment - 35
BMP - Utility Tree Risk Assessment - 36
BMP - Utility Tree Risk Assessment - 37
BMP - Utility Tree Risk Assessment - 38
BMP - Utility Tree Risk Assessment - 39
BMP - Utility Tree Risk Assessment - 40
BMP - Utility Tree Risk Assessment - 41
BMP - Utility Tree Risk Assessment - 42
BMP - Utility Tree Risk Assessment - 43
BMP - Utility Tree Risk Assessment - 44
BMP - Utility Tree Risk Assessment - 45
BMP - Utility Tree Risk Assessment - 46
BMP - Utility Tree Risk Assessment - 47
BMP - Utility Tree Risk Assessment - 48
BMP - Utility Tree Risk Assessment - 49
BMP - Utility Tree Risk Assessment - 50
BMP - Utility Tree Risk Assessment - 51
BMP - Utility Tree Risk Assessment - 52
BMP - Utility Tree Risk Assessment - 53
BMP - Utility Tree Risk Assessment - 54
BMP - Utility Tree Risk Assessment - 55
BMP - Utility Tree Risk Assessment - 56
BMP - Utility Tree Risk Assessment - 57
BMP - Utility Tree Risk Assessment - 58
BMP - Utility Tree Risk Assessment - 59
BMP - Utility Tree Risk Assessment - 60
BMP - Utility Tree Risk Assessment - 61
BMP - Utility Tree Risk Assessment - 62
BMP - Utility Tree Risk Assessment - 63
BMP - Utility Tree Risk Assessment - 64
BMP - Utility Tree Risk Assessment - 65
BMP - Utility Tree Risk Assessment - 66
BMP - Utility Tree Risk Assessment - 67
BMP - Utility Tree Risk Assessment - 68
BMP - Utility Tree Risk Assessment - 69
BMP - Utility Tree Risk Assessment - 70
BMP - Utility Tree Risk Assessment - 71
BMP - Utility Tree Risk Assessment - 72
BMP - Utility Tree Risk Assessment - 73
BMP - Utility Tree Risk Assessment - 74
BMP - Utility Tree Risk Assessment - 75
BMP - Utility Tree Risk Assessment - 76
BMP - Utility Tree Risk Assessment - 77
BMP - Utility Tree Risk Assessment - 78
BMP - Utility Tree Risk Assessment - 79
BMP - Utility Tree Risk Assessment - 80
BMP - Utility Tree Risk Assessment - 81
BMP - Utility Tree Risk Assessment - 82
BMP - Utility Tree Risk Assessment - 83
BMP - Utility Tree Risk Assessment - 84
BMP - Utility Tree Risk Assessment - 85
BMP - Utility Tree Risk Assessment - 86
BMP - Utility Tree Risk Assessment - 87
BMP - Utility Tree Risk Assessment - 88
BMP - Utility Tree Risk Assessment - 89
BMP - Utility Tree Risk Assessment - 90
BMP - Utility Tree Risk Assessment - 91
BMP - Utility Tree Risk Assessment - 92
BMP - Utility Tree Risk Assessment - 93
BMP - Utility Tree Risk Assessment - 94
BMP - Utility Tree Risk Assessment - 95
BMP - Utility Tree Risk Assessment - Cover4
https://www.nxtbookmedia.com