Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands. A new paper gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.
About 30 million people are dependent on the protection by coral reefs as they live on low-lying coral islands and atolls. At present, some of these islands experience flooding due to wave events a few times per decade.
Aerial photograph of Kwajalein Atoll in the Marshall Islands showing its low-lying islands and coral reefs. A new study gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.
Credit: Curt Storlazzi/USGS
Underwater image of a wave breaking over a coral reef on Kwajalein Atoll in the Republic of the Marshall Islands. This image shows how the high hydrodynamic roughness of live, healthy corals causes friction that induces breaking of waves over coral reefs, reducing wave energy at the shoreline that can cause flooding and island overwash.
Credit: Curt Storlazzi/USGS
It is expected that this rate of flooding will increase due to sea level rise and coral reef decay, as the remaining dead corals are generally smoother in structure, and do less to dissipate wave energy. Loss of coral cover not only causes increased shoreline erosion but also affects the sparse drinking water resources on these islands, which may eventually make these islands uninhabitable.
In order to prevent or mitigate these impacts, coastal managers need know to what extent their reef system may lose its protective function so that they can take action. The new study by researchers from the Dutch independent institute for applied research Deltares and the U.S. Geological Survey gives guidance on a local reef’s sensitivity to change. The new research has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
To gain insight into effects of changing conditions on coral reefs, the study authors used Xbeach, an open-source wave model. The computer model was first validated using field measurements obtained on the Kwajalein Atoll in the Marshall Islands in the Pacific Ocean, and was then used to investigate what the effects on water levels, waves, and wave-driven runup would be if certain reef properties change. Reef roughness, steepness, width and the total water level on the reef platform are all important factors for coastal managers to consider when planning mitigating measures, according to the study’s authors.
The results suggest that coasts fronted by relatively narrow reefs with steep faces and deeper, smoother reef flats are expected to experience the highest wave runup and thus the greatest potential for island flooding.
Wave runup increases for higher waves, higher water levels that are expected with sea level rise, and lower bed roughness that occurs as coral degrades and becomes smoother. These are all expected effects of climate change. Rising sea levels and climate change will have a significant negative impact on the ability of coral reefs to mitigate the effects of coastal hazards in the future, according to the new study.
The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.
Deltares is an independent institute for applied research in the field of water and subsurface. Visit http://www.deltares.nl
USGS provides science for a changing world. Visit USGS.gov
Notes for Journalists
A PDF copy of the article is available by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2015GL064861/abstract?campaign=wlytk-41855.5282060185
Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at firstname.lastname@example.org. Please provide your name, the name of your publication, and your phone number.
Neither the papers nor this press release is under embargo.
“The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines”
Ellen Quataert: Department of Applied Morphodynamics, Deltares, Delft, Netherlands; and Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands;
Curt Storlazzi: Pacific Coastal and Marine Science Center, U.S. Geological Survey, Santa Cruz, California, USA;
Arnold van Rooijen: Department of Applied Morphodynamics, Deltares, Delft, Netherlands;
Olivia Cheriton: Pacific Coastal and Marine Science Center, U.S. Geological Survey, Santa Cruz, California, USA;
Ap van Dongeren: Department of Applied Morphodynamics, Deltares, Delft, Netherlands.
Contact Information for the Authors:
Curt Storlazzi: +1 (831) 295-3429, email@example.com
Ap van Dongeren: +31(0)88335 8351, firstname.lastname@example.org
+1 (202) 777-7524
+1 (650) 329-4006
Mariska van Gelderen
+31 (0)6 13 67 13 70
Nanci Bompey | American Geophysical Union
Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen
Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research