Keeping the beach above water

The beach at St. Peter Ording is to a large extent unique, but despite its huge dimensions its long-term future is at risk. As part of a major project, a small team of geoscientists from Kiel University have dedicated themselves to tackling this problem.

White beach at St. Peter Ording with blue sky
© pur.pur

An idyll with special features: the beach at St. Peter Ording (archive photo).

Entitled "Sandküste St. Peter Ording" (St. Peter Ording sandy coastline), a remarkable initiative has been set up on the west coast. With great commitment at both a practical and scientific level, interested parties and those who will potentially be affected by this in the future joined forces locally to create the conditions required to maintain the impressive beach landscape along this section of the North Sea coast for as long as possible.

Coordinated by the Wadden Sea Office of the WWF (World Wide Fund for Nature), the Deich- und Hauptsielverband Eiderstedt (Eiderstedt water board), Naturschutzgesellschaft Schutzstation Wattenmeer (Wadden Sea nature conservation association), Kiel University and Technische Universität Braunschweig are all on board in the project.

The experts from the Leichtweiß-Institute for Hydraulic Engineering and Water Resources at Technische Universität Braunschweig are considering the matter from an engineering perspective and focusing on the resilience of dunes as natural elements of coastal protection. On behalf of Kiel University, the working group on Coastal Geology and Sedimentology at the Institute of Geosciences, led by Professor Christian Winter, is concentrating on what is happening in front of the dykes and dunes.

"How does a beach work?" said working group leader Winter, formulating the all-important question, which in detail has a lot to do with the transportation of sediment by waves, currents and wind.

It is a known fact that the spectacular beach at St. Peter Ording is largely due to the interplay of these factors. In the 1980s, they were responsible for forming a very large sandbank that was pushed up against the coastline, practically creating a double beach.

Doctoral candidate Clayton Soares aims to find out what lies deeper behind these processes. He is developing numerical computer models, which he then compares to real data, for instance, about local wind and current conditions. If there are sufficiently clear similarities, in the next step it is possible to analyse with some degree of reliability what happens, for example, if one component in the system changes but all the others remain the same.

"That sounds simple, but involves a great deal of effort," said the young researcher. Despite extremely effective technology, he said, the computer can sometimes rattle away for up to 14 days to depict certain scenarios. "This is because Clayton is running very detailed models in order to get results that are exact as possible," explained Professor Winter.

Despite taking such a meticulous approach, science still cannot predict the future. It would be ideal if those responsible for St. Peter Ording knew exactly what was in store for their coastline in 100 years, but even with the best will in the world, said Christian Winter, this is not possible. "We cannot make predictions like that, quite simply because we do not know the framework conditions. Even weather forecasts, which are nowhere near as complex, are only reliable for a few days ahead."

Nevertheless, the professor and his doctoral candidate are confident that they can make a useful contribution to the "Sandküste St. Peter Ording" project. Among other things, this concerns estimations of the phenomenon of how transportation processes lead to the beach being reshaped and relocated. From a scientific standpoint, these types of effects and even the large-scale disappearance of beaches are by no means unusual, they are completely natural. "Coastlines strive for balance," said Professor Winter. "If the sea level rises, they shrink, if it falls, they expand." It only becomes problematic due to the interests of people who work there, use them for tourism and like to build their houses as close to the sea as possible. And therefore it seems very much the case that it is in everyone’s interests to contribute to coastal protection so that these coastlines can be enjoyed for as long as possible.

Author: Martin Geist

 

The "Sandküste St. Peter Ording" (St. Peter Ording sandy coastline) project offers lots of opportunities for all interested parties to get informed and involved. More information is available at www.sandkueste-spo.de