Wind Resource - Wind Energy: Renewable Energy and the Environment - page 66

FIGURE 4.13 Examples of flagging of trees: left, tree on plains, Canyon, Texas (6 m/s average wind speed at
10 m height); right, tree at South Point, Hawaii (10 m/s average wind speed at 10 m height).

Prevailing wind

Side
view

Side
view

To p
view

To p
view

0
No
deformity

I
Brushing and
slight flagging

II
Slight
flagging

III
Moderate
flagging

IV
Complete
flagging

V
Partial
throwing

VI
Complete
throwing

VII
Carpeting

FIGURE 4.14 The Griggs-Putnam Index of tree deformation.