The Future of Natural Hazards in Switzerland

Growing risk of floods in the Aare catchment due to climate change

Conclusion

In the discussion, we addressed the difference of the high-altitude regions with the lowlands. It was pointed out that the high-altitude regions have a smaller resilience to high discharge due to low pretention capacity of their waterways. On the other hand, they have a higher resistance, since the flood events are expected to be of short nature.


The lowlands have a high resilience to floods and thus it is more unlikely for floods to happen. However, the resistance of those areas is low since for once, the floods are expected to be of longer nature and for the other way more critical infrastructure could be damaged.


Calling back to the research question, it can be stated that especially the mountainous areas are more likely to be affected by high discharge due to a climate change-based increase of precipitation. The damage potential for those areas however is lower than for the flatlands. It is especially the frequency which is troublesome. For the lowlands, it is important to be aware of the huge damage potential in case of a flood. Due to the different natures between the high- and the lowlands (frequency vs. damage potential), it is important to be aware of its implications. For the mountains, direct mitigation measures could be of help through engineering approaches. The lowlands on the other hand could profit immensely from long term counter measures such as adequate spatial planning standards accounting a change in degree and frequency of flood events.


As for the quantification of the livelihood damage caused by high discharge based floods, it is difficult to assess if frequency, number of people affected and implications towards the livelihood. Similar applies to the financial aspects. Are 100 events in an area with little settlement more expensive to repair than one within areas where there is a lot of settlement, people and critical infrastructure? This is somewhat an ethical and philosophical question. More detailed and fine grained analyses of the specifically affected infrastructure for even more numerous and distinct scenarios could give further insights to this question.


What can be concluded is, that the mountainous areas will be more likely to be affected by climate change based strong precipitation, discharge and flood events. Non the less, the greatest damage potential remains within the regions of greater, but far away from absolute resilience to such events.