Abstract
Natural hazards have always affected human settlements, causing damage and fatalities and forcing people to adapt and to protect themselves. In recent years, the number of affected people and the economic impacts connected to natural hazards has significantly increased, mainly due to bigger investments in hazard prone areas. Moreover, climate-related natural hazards are expected to rise in the future triggered by climate change.
The Alps constitute a representative example of this phenomenon. The occurrence of natural hazards in populated areas, characterised by widespread tourism activities and highly valuable infrastructure, generates a high demand for risk management. Risk can be tackled by reducing the risk-exposed areas through limitation on settlements or by adopting grey or green protection measures, one of this being ecosystem-based solutions. Ecosystems such as forests can act as natural modifiers of hazard processes. In mountain environments, forested areas have been managed for a long time due to their protection effect against gravitational natural hazards such as avalanches, landslides and rock falls. Well managed forests are able to reduce both frequency and magnitude of certain hazardous processes and also their potential consequences on humans and their belongings. It is often argued that, although green measures are not immediately effective, they can adapt to different natural hazard conditions over time. Moreover, they are often less costly to install and to maintain compared to technical measures.
Nevertheless, the efficiency of forests in natural hazard regulation could be affected by climate change. Variations in precipitation and increasing temperatures can have a direct impact on forests, modifying their current composition and spatial distribution. The failure or decrease of the protective role of forests could eventually lead to indirect impacts to human settlements. Therefore, climate change may have a two-fold impact connected to gravitational natural hazards: it can affect not only the processes themselves, but it can also influence the extent to which assets and people are exposed to natural hazards by impacting protection forest characteristics.
In this context, the Interreg Alpine Space project “GreenRisk4Alps” aims at implementing an ecosystem-based risk management strategy for natural hazards in the Alpine region, assessing the risk posed by gravitational natural hazards under different environmental scenarios. Thus, the costs, the protective effects and the acceptance of technical and forestry-based protection measures are analysed and compared, also considering the effects of climate change to protection forests.
This poster contribution will highlight the risk assessment methodological framework adopted in the “GreenRisk4Alps” project. Firstly, a multi-level exposure assessment evaluates the difference in exposure of assets under different forest scenarios. The spatially explicit analysis is complemented by a stakeholder workshop through which local knowledge on natural hazard risks and their management is acquired. This serves to locate risk hotspots where an economic evaluation of different risk reduction measures is carried out. Moreover, climate scenarios are calculated and used to evaluate how the forest and its protection function will be modified in the future due to climate change, complementing the risk assessment workflow. All this aims at providing recommendations for a forestry-based risk management strategy which considers current and future, social and environmental conditions.