USING GEOMETRY IN THE MEASUREMENT OF TREE HEIGHT
By David Everson
AEDEverson@aol.com
Philip Barbour High School, Philippi WV
Using an Abney Level and a soda straw it is possible for you to determine the height
of the trees in your ecosystem study area plots. All measurements must be taken carefully
in order for your calculations to be accurate.
Directions:
- Two teams members will be necessary to complete this investigation. You will
need an Abney Level (You may have to assemble one).
- Begin to measure the trees in your subplots by picking a location for your
tree that is level with the base of the tree. NOT ON THE HILL SIDE ABOVE OR
BELOW THE TREE!!
- Measure the distance from the center of the base of the tree(at the five foot
level) out to the location that you can see the top of the tree easily. This is
the Base Length Measurement. (See diagram 2)
- Using the Abney Level have one member of the group sight along the meter stick
and line up the top of the tree in the straw, this is line B (See diagram 1) The
second team member needs to stand at the side of the at the side and read the
measurement of the angle on the protractor. This reading needs to be subtracted from
90 in order to determine the acute angle. (Example, 90 - 60 = 26o)
- The Tangent Ratio (the ratio of the length of the side opposite the acute angle
to the side adjacent to the acute angle) is determined by using the acute angle and
reading off of the Trigonometric Ratios Table (See Table 1) in the Tan column. (Example 31 = .6009)
- You can then calculate the height of the tree by multiplying the Tangent Ration
by the Base Length Measurement.
Example:
Base Length Measurement = 40m,
Acute angle = 16,
Tangent Ratio of .2867
The Base Length Measurement X Tangent Ratio = Tree Height
40 m X .2867 = 11.46 m
|
|
|
Activities-To-Go Index
