Question

Give reason to explain each of the following : Wind vane should not be placed over buildings and trees.



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Answer 1

Answer:

Near the ground, obstacles such as buildings and trees cause winds be deflected or swirl around, so that it is not possible to determine the correct wind direction. Anemometer and wind vane are placed at places where no nearby taller objects can interfere with the air movement.

Answer 2

Answer:

The flow of the wind is affected by obstacles such as buildings or trees. The air pressure build up against these obstacles causes the wind flow to (a) change direction and (b) to become more turbulent.

The change of direction would cause the wind vane to miscalculate.

The increased turbulence would make measurements more unstable as well as reduce the lifetime of the instrument (rapid movements causing increased friction).