Forests for natural hazard risk reduction: economic benefits and challenges Luuk Dorren Principle of natural hazard risk prevention 1. Avoiding / evading (hazard maps) 2. Biological measures (protection forests) 3. Technical measures (protective constructions) 4. Organisational measures (monitoring, evacuation/closure, temporal object protection, …) Benefits of protection forests 1. Forests simultaneously mitigate multiple natural hazards 2. Forests have a higher life expectancy and are cheaper than technical protective measures – they reduce maintenance costs of existing technical measures 3. Forests provide additional functions such as biodiversity, water filtering, wood production, recreation / tourism, etc. Key figures on protection forests in CH • Yearly investment ~ 145 Million € (40% by the Confederation) • Total area: ~ 585‘000 ha (50% of forest area CH) 50 km Valuating protection forests 1. Avalanche risk reduction Switzerland: 75 Million € / year (~ 100‘000 ha) 2. Rockfall risk reduction: 45’000 € / year (50 ha study area) 3. Protection value ≥ wood production value (~ 500 € / ha * year) 4. Steel avalanche barriers 950‘000 € / ha; wooden avalanche barriers 330‘000 € / ha; forest management ~ 20‘000 € / ha Accounting for infrastructure closure Challenges • Quantifying the effect of forests against shallow landslides, debris flows and floods • Better methods for calculating risk reduction due to the protective effect of forests • Prevention of negative effects of forests during extreme events More information luuk.dorren@bfh.ch Bern University of Applied Sciences Tel. +41 31 910 2978 Int. association for natural hazard risk management w w w . e c o r i s q . o r gg