Protecting lives and preventing property damage in Denmark’s Limfjord

We gave the Danish Costal Authority (DCA) the tools needed to examine future problems involving flooding in the Limfjord.

Located in Northern Denmark, the Limfjord is an estuary with two openings, one of which is the Thyborøn Channel. The six cities – with a total population of more than 60,000 people –situated around the fjord, have previously experienced flooding during storms. This was caused by:

• wind set-up in the fjord
• an inflow of water though the channel from storm surges in the North Sea

Over the last 100 years, there has been a dramatic increase in the cross sectional area of the Thyborøn Channel. We investigated the effects of this on the high water levels in the Limfjord. Based on this, we predicted future storm surge conditions if the erosion continues.

Using MIKE21 HD (our two-dimensional hydrodynamic modelling software) we established new high water statistics in the Limfjord based on:

• simulated surge conditions for 31 storms over a 33-year period
• the configuration of Thyborøn Channel in the present (2005), in the past (1958) and in future (2060)

Our modelling helped to determine the correlation between erosion and storm surges, as well as the possible impact of climate change. This enabled the DCA to examine possible problems with flooding in the Limfjord in the future. As such, the DCA was able to advise the Danish Ministry of Transport on the best solution to alleviate the flooding risks.