Prof. Dr. Annegret Thieken
Professor for Geography and Disaster Risk Research Group, Institute of Environmental Science and Geography, University of Potsdam
We have seen more and more extreme weather situations in Germany in recent years. How has this changed the focus of disaster risk management?
Time and again, extreme weather, such as heavy rain or heat, catches us unprepared and results in huge damage, particularly in cities. In cities, you have a lot of material assets – in other words buildings and infrastructures – as well as people concentrated in comparatively small areas. Urban structures themselves can also cause an increase in weather events and their effects. Impervious surfaces, for example, increase the quantity of surface runoff. To put it more simply: Less rain trickles away and when intensive rain falls this can result in flooding if the canalization system is unable to drain the water off.
Dense urban structures can also create heat islands in the summer. Cooling down at night is less in cities than in the surrounding countryside. As a result, urban populations suffer more negative health impacts due to heat. During the summer of 2018, the Robert Koch Institute (RKI) recorded 490 heat-related deaths in Berlin alone. The heat represents a particular problem for older people due to the strain it places on their cardiovascular systems.
There are many areas research can examine to avoid or reduce the effects of extreme weather. Regional development planning and urban planning are two areas which play a particularly significant role in avoiding the damage caused by natural hazards The question is, how best to do this: What are the most effective starting points for climate adaptation and disaster risk reduction in planning?
Creating a green city is an effective way to cushion the effects of both heavy rain and heat waves. But how can we create more green areas or green our buildings or prevent existing green areas from being built on? How can we ensure water supply for plants during dry and hot summers?
How can adapting protect us from future heavy rain events?
About one year ago, we conducted an online survey in Berlin as part of the German Research Foundation funded research training group “NatRiskChange”. We asked people who had been affected by heavy rain in recent years about the impacts as well as the warning and preparation for such events. We will be publishing a report shortly on our website (www.natriskchange.de). Due to the impact of COVID-19, it has not been easy to motivate enough people to take part. As such, the results need to be interpreted cautiously.
Our data show that heavy rain, such as experienced in and around Berlin in 2017 and 2019, can have a number of effects. This is not just restricted to damage to cars or flooded basements but also impacts in many ways on everyday life. This is a particular problem for people looking after other persons. This is something that needs to be better addressed by disaster aftercare. There are also things that people can do themselves to avoid damage. For example, installing a storm warning app or checking regularly to find about bad weather reports; devising an emergency plan for your household, placing important documents in a single folder and having an emergency case ready. Look to see how water can make its way into your house: How are driveways, entrances and basement windows designed? Often, even small upstands and foundation curbs help to make these routes flood-proof. There are already plenty of good tools and guidance, such as the Flood Passport, to help make a building more flood resistant.
What future synergy effects would you like to see from the Climate Change Center Berlin Brandenburg initiative?
The NatRiskChange research training group and the geoscience Netzwerk X are outstanding examples of successful cooperation between research institutions in Berlin and Brandenburg. I am looking forward to exciting projects, close and productive cooperation and new ideas from the Climate Change Center Berlin Brandenburg.
The interview took place in April 2021.