Flood risks mapped by improved basic data

Public authorities, homeowners, and businesses are now able to use much more detailed data to predict the consequences of high water levels, because the underlying data for a number of freely available analytical tools has been updated. This has provided a basis for a more effective emergency response and improved flood prevention.

A solid data basis makes it easier to manage important societal challenges. This is not least relevant for climate-change adaption, where new and much more detailed data makes it possible to simulate the direction of surface-water flow and predict where it will accumulate during extreme rainfall or increased water levels.

Everyone has access to the data

One of the tools that has been updated with the latest data is available at klimatilpasning.dk. “Havvand på Land” (“Seawater on Land") enables everyone to predict potential flooding in connection with storm surges. The combination of hydrological elevation models and aerial photos makes it easy to foresee where flooding might occur.

Users themselves can therefore obtain an overview of the different situations by visualising different levels of flooding. Below, we have taken a closer look at the City of Aabenraa and simulated conditions with water levels one-meter above normal. The blue colour indicates areas that are in danger of being flooded.

Data used for both emergency response and prevention

The new data consists of much more detailed data on land elevation in Denmark combined with a new cohesive dataset for watercourses and lakes, with watercourses channelled through pipes included as part of the nationwide watercourse network.

Even prior to this quality improvement, the data has proven useful for Danish fire and rescue services.

During the storm surge in January this year and during the storm Urd, authorities used the data to prioritise the most effective measures and to minimise the risk of damage from increased water levels.

The data forms the basis for preventative measures through climate change adaption during the planning of construction projects, as well as for mapping the flood risks for buildings, infrastructure, heritage sights, etc.

Common public sector collaboration behind the models

The Danish Elevation Model is part of the common public sector basic data, and it is freely available to citizens, businesses, and the public sector. Previously, data was dispersed over a number of municipal and central government databases, and therefore it was impossible to combine data easily.

The common public sector Basic Data Programme therefore contributes to a more efficient public sector and to establishing the basis for growth and productivity in the private sector. For example, the data foundation of the hydrological elevation models has already been incorporated into a number of new services developed by private businesses.

The Danish Agency for Data Supply and Efficiency (SDFE), Local Government Denmark, Danish Regions and the Danish EPA have spearheaded this part of the Basic Data Programme.