A new report on and model of damage costs from DTU will help Danish municipalities assess the risk of flooding and which costs they can expect flooding to incur for buildings, cultural assets, and nature.
More and more Danes are now experiencing the consequences of water in their basement or moisture damage in a holiday home following heavy rain. The cyclone Bodil, which swept across Denmark in 2013, caused damage from flooding that totalled almost DKK 900 million.
In the light of future climate change, such damage is only expected to increase. Therefore, Danish municipalities have been charged with planning Denmark’s climate adaptation, and mapping where there is a risk of flooding, and the damage that might occur.
To support this work, DTU Management has recently published a report that shows the potential economic damage of future storm surges along the entire Danish coastline based on assumptions about how much the sea is rising, and how strong storms are expected to be in future.
“We have calculated the cost of damage in each Danish municipality in the event of a storm surge based on two key factors—the total property values based on local sales prices and the claims paid by insurance companies. The calculations are useful for the municipalities and their climate adaptation, because they can help to shed light on local risks of flooding and the value of threatened properties at a time when prices for both all-year and holiday homes are exploding,” says Senior Researcher Morten Andreas Dahl Larsen, who is behind the report.
New model points the way in climate adaptation
An important background for the report is a new free damage cost model which has been developed by DTU Management in collaboration with the consulting engineering company LNH water Aps, and which municipalities can use to calculate the costs of flooding locally.
“What is new and very special about DTU’s damage cost model is that it can be used to calculate financial impact at a very detailed geographical level and for many sectors. In this way, the municipalities can more easily create an overview of what happens if water reaches buildings, businesses, transport infrastructure, heritage assets, nature, people etc.,” says Professor Kirsten Halsnæs, who has led the model development.
The model provides a sound basis for planning climate adaptation, because it can show where it is important to take action locally, where damage is likely to be significant, and where good solutions can be found. This is a step forward compared to existing models, which usually calculate insurance claims for buildings in the event of flooding, but which do not include a financial damage calculation for each sector.
“The model has initially been developed to calculate damage from flooding from the sea, but by adjusting the building area slightly, it can also be used to calculate damage from cloudbursts. Here, it has become a legal requirement to conduct sector-based financial damage calculations,” explains Kirsten Halsnæs.