Mangroves along the coasts of the Caribbean islands can significantly weaken storm waves, and a new calculation method now makes it clear how effective that natural protection really is. Scientists from China and the Netherlands have jointly developed a simple technique to predict how much waves are reduced by mangrove forests, even during severe storms. The method could provide important tools for coastal managers on islands such as Curaçao, Bonaire and Aruba, where mangrove areas are increasingly under pressure.
The calculation method, developed by Sun Yat-Sen University in China and the Royal Netherlands Institute for Sea Research (NIOZ), is based on data from extreme storms worldwide. During a typhoon in China, new measurements were taken. The researchers found that a mangrove forest about 100 meters wide can reduce storm wave height by half. This makes these ecosystems a powerful natural defense against flooding and coastal erosion.
The so-called HU method is easier to apply than existing models, which often require complex data about trees and water flows. “With this new approach, even coastal managers in less affluent regions can quickly assess how well their mangroves provide protection,” says Tjeerd Bouma of NIOZ.
According to Bouma, the method creates opportunities for sustainable coastal management. “Mangroves are not only natural wave breakers. They also capture carbon, filter water, and provide habitat for countless species. Restoring and protecting these forests is therefore not only useful during storms, but also for the broader ecological health of islands.”
The HU method uses the relationship between wave height and the so-called Ursell number, a measure of wave non-linearity. The method can be applied with limited field measurements, which makes it accessible for local governments, nature organizations, and engineers. The researchers plan to further develop the approach into an online tool or app.
The study has been published in the scientific journal Proceedings of the National Academy of Sciences (PNAS) and emphasizes that natural solutions, such as mangroves, can save billions worldwide in coastal defense.
