Investigating the role of coral reefs in wave dissipation

Coral reefs including complex structures of several meters over reef slopes (e.g., spur and groove) play a role in the dissipation of storm wave energy (e.g., Perris et al., 2024) and can reduce storm wave energy by 97% (Ferrario et al., 2014). Therefore, coral reefs are important natural breakwaters and have inspired interests in artificial reefs as coastal protection.

The complex topography of reefs induces drag on the flow, but the relationship between reef morphology and energy dissipation remains poorly understood. One of the reasons is that direct measurements of coral reef topography were previously difficult because large vessels cannot go in shallow water regions.

However, recently measurement has become possible using multibeam echo sounders installed in small vessels (e.g., Kan et al., 2015) and autonomous systems. In this project, the role of coral reefs in wave dissipation will be investigated using a detailed reef topography (Okinawa region in Japan) whose resolution is several ten centimetres based on three-dimensional storm wave modelling using a supercomputer. This research will be interdisciplinarily conducted with overseas researchers who have the knowledge to measure and have detailed coral reef bathymetries.    

The objectives of this research are as follows:  

1. Investigating wave dissipation effect due to coral reef topography by three-dimensional storm wave simulation.  
2. Identifying the coral reef shape with the most significant wave dissipation effect
3. Optimise the design of an artificial reef for wave dissipation and testing through scaled flume experiments.
    

As well as Dr Masashi Watanabe, Dr Hachem Kassem, and Professor Joerg Wiedenmann, you will also be supervised by organisations other than the University of Southampton, including: 

• Professor Hironobu Kan from Kyushu University, Japan