Samenvatting

Recently, the Inverness, Ross and Skye forest district has had multiple occasions of wind damage in their forests. Because these were unpredicted and costly events, the model used to predict wind damage, ForestGALES, was analysed. Both input and output of the model were closely examined to discover why it does not do what it is supposed to do; minimise wind damage. For the district this had multiple reasons, a major one being unawareness of the existence of the model. Furthermore, the quality of the input and therefore the results often contained large errors. Finally, the output could not be generated automatically districtwide. During this research, availability, quality and comprehensibility of the model were improved. This was done by investigating recent windblow and its causes throughout the district. Besides this, the demands of stability data from the district were researched. The input of the model for Inverness, Ross and Skye Forest District has, on this basis, been revised. Stand data were adjusted per species and per forest block. Factors affecting stability, such as rooting, wind direction and exposed edges, were analysed and considered in the new calculations. This, in turn, gave more information about the causes of windblow and thereby the ways of preventing it.