Nav: Home

Historic floods reveal how salt marshes can save lives in the future

June 29, 2020

YERSEKE (THE NETHERLANDS), 29 JUNE 2020 - Coastal wetlands like salt marshes are increasingly recognized as valuable natural defenses that protect coasts against strong wave attacks. Yet their performance during real-world, extreme storms has rarely been told. By digging into major historic records of flood disasters, a research team led by scientists from the Royal Netherland Institute for Sea Research (NIOZ), Delft University of Technology, Deltares and Antwerp University, reveal in a publication this week in Nature Sustainability that the value of nature for flood defense has actually been evident for hundreds of years.

Salt marshes have reduced the number of dike breaches during the well-known 1717 historic flood disaster. More interestingly, the 1953 flood disaster also tells us that salt marshes are not only 'wave absorbers' that ease wave attacks on the dike, but are also 'flood fighters' that lower the flood depth by limiting the size of breaches when the dike would fail during severe storms. And having smaller and shallower breaches because of salt marsh protection can save many lives.

Salt marshes have made dikes more stable during severe historic storms

Rising sea levels and stronger storms raise coastal flood risks and inspire development of new strategy of flood dense: supplementing engineered structures with coastal wetlands like salt marshes. Although we have learnt from experiments and models that these natural buffers are 'wave absorbers' that reduce storm impact, it is unclear whether and how they can indeed add considerable safety to engineered defenses during severe, real world storms. 'Evidence from two notorious flood disasters that killed thousands of people after dike breaching: 1717 Christmas flood and 1953 North Sea flood, however, show that salt marshes have already displayed their role of 'flood fighter' for hundreds of years', says Zhenchang Zhu, the leading author of this paper, who conducted this research at NIOZ, but is currently working at Guangdong University of Technology, China. 'Salt marshes not only reduced the number and total width of dike breaches during the 1717 Christmas flood, but was also found to confine the breach depth during the 1953 North Sea flood. Especially the latter, previously unknown function of natural defenses, can greatly reduce flood damage by lowing inundation depth', Zhu continues.

Protected by salt marshes during dike breaches: how does it work https://www.nioz.nl/en/expertise/wadden-delta-research-centre/news-media/videos/coastal-protection/protected-by-salt-marshes-during-dike-breaches-how-does-it-work

Hidden value of natural defense inspires novel flood protection designs

What can we learn from historic lessons? 'Flood defenses combining green and gray features are actually more beneficial than considered earlier. Beyond wave attenuation, salt marshes can lower flood impacts simply by limiting the size of dike breach, and continues to do so under sea level rise', Zhu adds. This generally overlooked function of salt marshes is actually more applicable than wave dissipation, as it is not limited to wave-exposed locations. To harness natural defense, marshes ideally have to be preserved or developed at the seaside of the dike to buffer the waves. This may, however, not always be possible. The study implies that even in this situation, it may still be possible to enhance coastal safety by creating salt marshes in between double dikes, where a secondary more landward dike is present and the most seaward primary dike is opened to allow natural processes to ensure marsh development. Despite no longer useful for wave reduction, such marshes are still very helpful for flood protection by making the landward dike more stable during extreme storms and buffer the effects of the rising sea in the long run. 'Overall this research enables novel designs of nature-based coastal defenses by smartly harnessing different natural flood defense functions', says Zhenchang Zhu.

For more information about the future use of double dikes in Zeeland, see also:

Double dikes for flood safety https://www.nioz.nl/en/expertise/wadden-delta-research-centre/news-media/videos/coastal-protection/double-dykes-for-flood-safety
-end-


Royal Netherlands Institute for Sea Research

Related Salt Articles:

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.
New technology helps reduce salt, keep flavor
A new processing technology out of Washington State University called microwave assisted thermal sterilization (MATS) could make it possible to reduce sodium while maintaining safety and tastiness.
The salt of the comet
Under the leadership of astrophysicist Kathrin Altwegg, Bernese researchers have found an explanation for why very little nitrogen could previously be accounted for in the nebulous covering of comets: the building block for life predominantly occurs in the form of ammonium salts, the occurrence of which could not previously be measured.
Salt helps proteins move on down the road
Rice chemists match models and experiments to see how salt modifies surface interactions in chromatography used to separate valuable drug proteins.
Mars once had salt lakes similar to Earth
Mars once had salt lakes that are similar to those on Earth and has gone through wet and dry periods, according to an international team of scientists that includes a Texas A&M University College of Geosciences researcher.
Marathoners, take your marks...and fluid and salt!
Legend states that after the Greek army defeated the invading Persian forces near the city of Marathon in 490 B.C.E., the courier Pheidippides ran to Athens to report the victory and then immediately dropped dead.
Water solutions without a grain of salt
Monash University researchers have developed technology that can deliver clean water to thousands of communities worldwide.
Solving the salt problem for seismic imaging
Automated imaging of underground salt bodies from seismic data could help streamline oil and gas exploration.
Higher salt intake can cause gastrointestinal bloating
A study led by researchers at the Johns Hopkins Bloomberg School of Public Health found that individuals reported more gastrointestinal bloating when they ate a diet high in salt.
Table salt compound spotted on Europa
New insight on Europa's geochemistry was hiding in the visible spectrum.
More Salt News and Salt Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.