Enabling Heureka model to generate random storm events
Even though the growth of Swedish forests may increase due to changing climate, natural disturbances caused by weather extremes such as storms, droughts etc., are also likely to increase in the future. However, projections of these stochastic events are highly uncertain. Storms are a major problem for growing stock across Europe, including Sweden. Forestry relies on simulations using Decision Support System such as Heureka to predict future tree growth and plan management actions accordingly. Heureka’s storm module is built using the past storm events from 1953 – 2013, where the storm-fellings are recorded. Even for future simulations, past recorded storms are repeated with the same intensity and frequency into a deterministic scenario, becoming in an unrealistic ad hoc approach.
This project aims to develop Heureka’s functionality to simulate stochastic storm events for future simulations based on the past recorded storm events.
We have developed a new R-code to be used for any user to simulate a wind storm in a stochastic scenario, based on all the 132 past storms occurred in Sweden from 1953 – 2013, where the storm fellings were recorded. The user can also increase or decrease both the wind intensity and frequency of storms by a percentage value to recreate hypothetical future scenarios.
This project aims to develop Heureka’s functionality to simulate stochastic storm events for future simulations based on the past recorded storm events.
We have developed a new R-code to be used for any user to simulate a wind storm in a stochastic scenario, based on all the 132 past storms occurred in Sweden from 1953 – 2013, where the storm fellings were recorded. The user can also increase or decrease both the wind intensity and frequency of storms by a percentage value to recreate hypothetical future scenarios.
The figure represents some examples of the output from the new stochastic storm simutation and the default storm settings in Heureka model. The y-axis is the maximum wind speed during the storm events which represents the intensity of each storm event. X-axis is the year in which the storms are happening. Default storms is the default settings of storm intensity and frequecy currently implemented in Heureka model. All others are randomized storm distribution usign the new R-code and the Heureka software.
Preliminary conclusions
Heureka user can test with different intensities and frequencies of storms in the forest landscape and analyze their impact to Swedish forestry. This output could be a very interesting future research line due to the economic and ecological importance of windstorms in Sweden. Forest managers and policy makers could be interested in the output of the present project, so new policy recommendation and silviculture guidelines could be arise from it. Any user can utilize the R-code to run their own stochastic storm scenario in Heureka to obtain a realistic future scenario and check different forest management strategies to deal with the risk of windstorm damage.
This project has received funding from the Forest Damage Centre (SLU) to Jorge Aldea- Narayanan Subramanian in 2021.