Calculating wind risk
ForestGALES calculates the probability of wind damage to a stand in two stages by looking at information from the trees and the site.
Using information from the trees:
and then the site:
- soil type
- rooting depth
ForestGALES then calculates the critical wind speed at which trees will be damaged, either by uprooting or stem breakage, and its likely return period based on stand location.
Detailed Aspect Method of Scoring (DAMS)
The probability of damaging winds occurring is then calculated using information on the wind climate throughout Britain as classified in the DAMS scoring system. DAMS is a modelled windiness score calculated from tatter flag observations, elevation, aspect, topographical exposure, valley shape and direction.
DAMS values can be:
- Calculated for a specific location directly; or
- Looked up from the DAMS scores for the whole of Britain.
This information can be used to assist stand management decisions, for example felling age, silvicultural practice and cultivation.
Throughout its development, ForestGALES was designed in consultation with representatives of both private and state forestry organisations and is designed to be easy to use and includes extensive on-line help.