Decision Support System For Risk Management A Case Study

Don) stands in Himi region, Toyama Prefecture, Japan.

A wind risk management (WRM) tool, Forest TYPHOON, was developed using a modified version of GALES and the airflow model WAs P.

Forest TYPHOON has already been developed and validated using typhoon wind damage data from Himi by Kamimura (2007).

The decision support approach was constructed from a growth model Silve-no-Mori, Forest TYPHOON, Arc GIS (ESRI Ltd, Redlands, CA) and the decision tree algorithm CART.

Consequently, such damage has not been studied from the long-term perspective of wind damage risk.

In other words, wind damages in forests were only observed on the basis of location, volume and area in order to determine economic losses (Matsuzaki and Nakata, 1994) and ignored the impact of crop characteristics and local airflow patterns.These tropical cyclones show similar phenomenon in the northern hemisphere where there is an eye at the centre with low pressure and a large counterclockwise revolving vortex (Foster and Boose, 1995).Typhoons usually move at between 5 and 15 m s and are associated with strong winds and heavy rainfall.The tools are based on directly linking tree mechanical behaviour and forest airflow to predict stand vulnerability and potential damage risk.Forest Research in Britain has developed a windthrow risk assessment model Forest GALES, which includes a predictor of wind climate named detailed aspect method of scoring (DAMS) (Quine and White, 1993) and a predictor of stand vulnerability named geographical analysis of the losses and effects of storms (GALES) (Gardiner , 2000).The decision trees showed that top height was the most important stand characteristic and provided a critical top height at which silvicultural treatments need to be modified.If the top height exceeds the critical height, any treatments including thinning should be avoided to minimize wind damage risk.The Toyamaru typhoon destroyed approximately 300 000 m (2003) statistically analyzed the data of abiotic damaged stands from forest insurance databases and found that planted forests older than 41 years are more likely to incur wind damage.The Forestry Agency showed that approximately 52 per cent of planted forests were more than 36 years old in 2002 ( thus, the extensive existing semi-mature and mature stands in Japanese forests could incur enormous damage from typhoons.However, these stands can be identified by key characteristics (e.g.height, stem spacing, stem taper, slope and aspect) to enable practitioners to make long-term forest management plans.