Climate Change to Increase Compound Flooding in Northern Europe

Coastal areas of Northern Europe will experience an increase in “compound flooding” in coming decades as a result of climate change, say researchers.

Compound flooding occurs where storm surges and heavy rainfall combine. Researchers say until recently this type of flooding in Europe was concentrated along Mediterranean countries.

However, compound flooding will greatly increase for Northern European countries in the future as the climate warms, according to a study recently published in Science.

This is the first study of compound flooding to consider future changes that could result from combined geographic shifts in precipitation, storm surges, waves and tides. The hazard of compound flooding is not usually included in coastal flooding risk analyses, even though storm surges and extreme precipitation runoff are related. What’s more, coastal cities are expected to further grow in the coming decades, underscoring an urgent need to assess future compound flooding probability.

Assuming a warmer future climate, the researchers found the probability of compound flooding risk is likely to increase heavily along the west coast of Great Britain, northern France, the east and south coast of the North Sea, and the eastern half of the Black Sea.

The Bristol Channel and the Devon and Cornwall coast in the UK, as well as the Dutch and German North Sea coast, are considered hot spots, with compound flooding events likely to occur more than once every six years. The threat is even worse near Noorderzijlvest in the Netherlands, where the compound flooding risk is expected to triple, and around Bergen on the Norwegian coast, where it may increase by fivefold.

Present probability of potential compound flooding (CF).
Future probability of potential compound flooding (CF)