State of the art flood mapping with new technology and the right skills

With the help of new technology and skilled Envidans, it is now possible to make really good flood maps with an extremely high level of detail at an affordable cost.


Together with Aarhus Municipality and Aarhus Vand, Envidan has taken flood mapping to the next level by implementing a hydrodynamic model simulation at 80 cm resolution with approximately 800 million calculation points. In comparison, the last mapping in 2016 only had 3 million calculation points.

Among other things, the model results have been used as input for an EAD-calculation at building level for the whole of Aarhus Municipality, so that an economic approach can provide the best starting point for the future planning of cloudburst water in terrain. In addition to the updated flood map, new web visualization modules have been developed to display and visualize the huge amount of data.

Head of Research and Development at Envidan, Mads Uggerby, has been responsible for the project, and he is proud of the results:

“As project manager, I can only say that I am extremely proud and impressed with how hard the team has worked and how they have been able to find solutions to close to impossible challenges.”

There is also no doubt that the task has required something out of the ordinary with the very large amounts of data. To be able to handle the task computationally, we have invested in two large calculators with GPU technology, which has enabled a total calculation time of only 3,5 months, despite the fact that the total amount of data produced in the project is approximately 43 TB.

The new flood mapping means that it is now possible to get an updated and very detailed overview of how water flows on the ground in Aarhus.