4.2 Climate Change and its relevance for the costs of alpine hazards
be quite significant. On the other hand, hazards which have considerably higher eco-nomic and social significance, such as floods and windstorms, have more complex and less certain linkages with climate change.”
Still, the international Platform on Natural Hazards of the Alpine Convention (PLANALP 2008) estimates that an annual budget of more than € 1 billion will be need-ed throughout the Alpine countries to adapt natural risk management to climate change.
Actions foreseen are i) the production and updating of hazard and risk maps and ii) their integration in land-use planning, iii) the establishment of networks to share knowledge and experience at regional, national and international level (risk dialogues) including iv) monitoring systems, event documentation and analyses, v) improvement of early warn-ing and emergency management as well as vi) an improvement and maintenance of technical measures (including testing their performance in case of overload and robust design; see PLANALP 2008).
→ Mountain ecosystems and hence human settlements as well as economic activities in these regions are very sensitive to climate variations and climate change. In general, the existing facts and estimates about climate change impacts in the Eu-ropean Alps show no robust and homogenous picture, but an intensification of fre-quencies and magnitudes of Alpine hazards is expected. It is evident, that there is an increasing risk of GLOFs and triggered floods or debris flows, an increase in permafrost degradation and coherent destabilization of precipices and a possible combination and series of reactions of these processes (multiple hazards). In the case of floods, a greater intensity and frequency of winter high waters could lead to substantial economic impacts, but the connections to climate change are not yet clear enough. These analyses are mostly based on short data periods, so results must be judged preliminary.
Table 4.1: Potential climate change impacts on natural hazards in the European Alps; Source: Observatoire National sur les Effets du Réchauffement Climatique (2008).
process climate change impact
Floods - increased winter precipitation increases flood risk, due to reduced snow cover and higher rain limit especially for regions of about 1000 to 2500 m a.s.l.
- simultaneous reduction of spring flood peaks and temporal shifting of floods back-wards to early spring
- glacial degradation triggers a short term increase of runoff geologic mass
movements
deep landslides:
- in general, acceleration of movement rates triggered by higher precipitation, but with respect on local preconditions
- re-activation of deep landslides more than activation of new processes rock fall:
- increase of events which are strongly correlated to permafrost degradation, but high uncertainty
- increase of frequency in the permafrost area influenced by freezing - unfreezing cycles due to rising temperatures
- simultaneous reduction of rock fall in lower altitudes
process climate change impact
torrential hazards - no clear modelled trend, but rising debris flow intensities
- intensity variation could release higher volumes and stopping distances - torrential hazards are highly dependent on local preconditions
- possible interlinkage with periglacial and glacial processes, more available material due to intensification of glacier retreat and permafrost degradation
- at low and medium altitudes decrease of debris flow events
- potential higher debris flow activity due to increased precipitation in spring and fall, but with a high uncertainty
- high mountain areas will be more affected by debris flow events, due to more fre-quent melting periods
avalanches - no trends have been observed regarding the frequency and changing locations - possible decreasing avalanche activity at low and middle altitudes due to reduced
snow cover
- increased avalanche activity at high altitudes, due to increased snow cover in-crease triggered by intensification of precipitation
- potential increase in slab snow avalanches due to higher variation of melting peri-ods and a higher snow/rain line
Table 4.2: Potential climate change impacts on natural hazards in the European Alps; Source: Jetté-Nantel & Agrawala (2007, p. 70).
Changes in natural hazards Confidence in projected damages
Most affected regions Economic importance
permafrost related hazards:
increase in frequency of rock fall and magnitude of debris flows
very high high mountain range, tourism areas low
GLOFs:
increasing incidence of Glacial Lake Out-burst Floods (GLOFs)
very high high mountain range, tourism areas low
other glacier related hazards:
increasing frequency and magnitude
high high mountain range, tourism areas low
winter floods:
greater intensity and frequency
medium lower mountain range, densely populated areas
very high
rockfalls:
increasing frequency
medium lower to medium mountain range medium
landslides and debris flows:
increasing frequency and magnitude
medium/ low lower to medium mountain range medium
avalanches:
increasing frequency and magnitude at high altitudes
low high mountain range, tourism areas medium
5 End-user views, recommendations and knowledge gaps on costs of Alpine hazards
Various case studies that were introduced in the preceding chapters illustrate that diverse methods exist for assessing different costs related to Alpine hazards. However, a consistent evaluation of the overall costs of Alpine hazards and risks as depicted in Fig-ure 1.10 is still missing. Nevertheless, interaction with stakeholders in the ConHaz-Project has shown that in the cost assessments in some Alpine Countries, particularly in Austria, Switzerland, but also Slovenia, are comparatively well developed and imple-mented. This chapter summarizes end-user views, best practices, research gaps as well as recommendations for future research. The chapter is mainly based on the literature review as well as the ConHaz-workshop “Costs of Alpine hazards” held in May 2011 in Innsbruck, Austria.
The workshop “Costs of Alpine Hazards”, held on 20th May 2011 in Innsbruck, Austria, and the preceding excur-sion on 19th May identified strengths and shortcomings of current methods for the assessment of costs of Alpine hazards. In addition, the needs of end-users were collected with regard to the type and form of information that should be provided in case of an event as well as for risk reduction plans. Further, experiences with current meth-ods as well as applications and impacts of broader and better information were compiled. The workshop particu-larly focused on methods of assessing costs and benefits due to natural hazards in mountain regions (e.g. collec-tion and assessment of real losses, methods to assess potential direct, indirect and intangible damage, methods and guidelines for cost-benefit-analysis of mitigation measures).
The workshop had three main pillars. In the morning session six key note lectures from the different hazards communities and Alpine countries were given. The presentations showed the plurality of different methods and hazards applied in the countries of the Alpine arc. Discussion sessions in the afternoon were based on the world-café-method to encourage a maximum of interaction between the participants. Moreover, the workshop partici-pants had the opportunity to fill out a questionnaire on the cost assessment for Alpine hazards.
In the afternoon sessions the following questions were discussed by the participants:
- What should a good approach for xxx include?
- Which approach for xxx does currently meet your requirements at best? Why?
- How can methods for xxx contribute to a better risk management or to a reduction of alpine risks?
- What do we still need to learn about xxx?
- How can we foster learning from past events and across hazard types, institutions and alpine countries?
- How can we support each other?
where “xxx” = Estimating 1. direct costs / 2. indirect costs / 3. intangible effects / 4. costs for mitigation & adapta-tion / 5. Collecting data about costs of alpine hazards
Five tables on the above-mentioned topics with each two moderators were established. Altogether, three discus-sion rounds took place so that participants had the chance to change the table/discusdiscus-sion topic.
At the end of the workshop the participants were asked to write a brief statement addressing two questions:
1) From what you have heard today: What was the most relevant for you?
2) What would be the most important next step?
The answers were collected and grouped to some overarching topics.