Scientists simulate real-world wave impacts on coral atolls to study future flood risks and explore limits of adaptation.
New hope for vulnerable island communities
A groundbreaking study using coastal models has revealed how natural coral atoll islands may respond to rising sea levels and more frequent wave-driven flooding. The research, led by Roelvink et al. [2025] and published in Earth’s Future, offers fresh insights into how sediment naturally accumulates on the ocean-facing side of islands, helping raise their elevation and reduce the impact of future overwash during extreme weather events.
These findings are particularly relevant for rural, low-lying islands in the Maldives and Pacific Ocean, where communities depend heavily on coral reef protection and are among the first to face the impacts of climate change.
Natural resilience and the role of sediment movement
The study highlights how sediment dynamics, driven by wave action, can naturally elevate parts of atoll islands, making them more resistant to flooding. Using coastal morphodynamic models, researchers showed that on Fiyoaree Island in the Maldives, sediment accumulation could reduce wave overwash risks by up to threefold under certain conditions.
Crucially, the study also reaffirms the importance of protecting coral reefs, which act as natural buffers by reducing wave energy before it hits the island. But this protection is under growing threat from rising sea surface temperatures, which are causing widespread coral bleaching. Even a 2°C rise in global temperature could challenge coral resilience, pushing researchers to explore the limits of adaptation in the face of climate change.
A lab-built island to test real-world impacts
To better understand how these islands might fare under rising seas and stronger storms, scientists have built a 50-meter scale model of a coral reef island at the Deltares Delta Flume the world’s largest wave flume, located in the Netherlands. The model replicates conditions seen in atoll islands of the Maldives and the Pacific, and over two months, it will be subjected to various wave and sea-level scenarios.
The flume can generate waves up to 2 meters high allowing researchers to simulate extreme events and monitor how the island responds in real time using wave sensors, video cameras, current meters, and laser scanners.
Testing artificial reefs for future protection
As part of the experiment, the team is also evaluating the effectiveness of eco-friendly artificial reef structures designed by Coastruction. These complex-shaped reefs, installed around the scale model, aim to replicate and restore natural reef functions slowing waves, reducing flooding, and offering new marine habitats.
Dr. Marion Tissier of Delft University of Technology says “This experiment provides a rare opportunity to test how reef restoration can protect island coasts, By measuring water movement through these complex structures, we can better understand their protective potential.”
Fieldwork in the Maldives: tracking real-world wave behavior
In addition to lab simulations, the research team has recently returned from a massive field study on Dighelaabadhoo Island in the Maldives, where over 80 instruments were deployed to monitor energetic wave activity during the Indian Ocean’s southwest monsoon season.
The data collected represents the largest field campaign ever conducted on an atoll island, with instruments remaining in place until August. The results will feed into future models and help scientists refine projections of coastal vulnerability and adaptation capacity.
Conclusion: nature’s defenses and the race against climate change
The study offers a promising look at how natural processes and targeted interventions may help protect some of the world’s most at-risk islands. However, researchers warn that without urgent efforts to reduce greenhouse gas emissions and safeguard coral ecosystems, even these adaptive responses may fall short in the face of accelerating climate change.
As Gonéri Le Cozannet notes this research not only opens the door to quantitative studies on adaptation limits, but also underscores the urgency of climate action to prevent irreversible damage to both ecosystems and human lives.