Saturday 8 August 2015

Grigg-Putnam Index

The Griggs-Putnam Index is one of several empirical methods of estimating the prevailing wind speed at a site by observing the growth patterns of trees. Strong winds will deform trees and shrubs so that they indicate an integrated record of the local wind speeds during their lives

IBrushing occurs when small branches bends downwards.
II-III-IVFlagging occurs when large branches bends downwards, and branches which are upwind are shorter than branches which are downwind.
V-VIThrowing occurs when the actual trunk of the tree curves downwind.
VIICarpeting occurs when the trunk grows along the ground.

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