Study reveals the value of coral reefs in the Red Sea

Researchers at KAUST are describing the valuable role of coral reefs in the Red Sea. Using high-resolution modeling, the team set out to predict peak wave heights and storm surges for city planning in the King Abdullah Economic City (KAEC) coastal zone.

The findings provide insightful data for infrastructural modifications, and also emphasize the economic and ecological value of coral reefs.

“The original task was to model the maximum wave heights to set the minimum safe floor elevation for structures and roadway design in the city,” explained study co-author Sabique Langodan. “Yet with the wealth of wave and water-level observations and accurate bathymetry (water depth) near the coastline, combined with the advanced modeling and supercomputing capabilities available to us at KAUST, we extended the study to investigate the role of coral reefs in modulating the wave climate of this reef-sheltered region.”

In order to predict extreme wave heights, the scientists used computer modeling to analyze how waves evolve as they pass across the shallow sea floor based on long-term data. 

“We configured a high-resolution model using an unstructured grid, which allows us to vary the resolution of the model over the domain, from 60 kilometer cells out to sea, to cells as small as 60 meters near the coastline,” said Langodan.

The computer model also accounted for other relevant information, such as atmospheric forcing and sea circulation.

“Our high-resolution study allowed the minimum safe elevation in KAEC to be revised lower, from 4.0 meters to 2.3 meters,” said study co-author Ibrahim Hoteit. “Although a relatively small drop, this leads to a saving of about 90 million cubic meters of fill material equating to about 500 million USD.”

However, the lowered safe elevation height was dependent on the presence of coral reefs located off the Red Sea coast, which act as a natural breakwater, providing protection from hazards such as flooding and erosion.

“The reefs reduce wave heights by half at the coastline,” said study co-author Omar Knio. “Reef protected coastlines could still be at risk of larger waves if the coastal protection offered by reefs is reduced by coral degradation or sea level rise.”

The study is published in the journal Ocean Engineering.

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By Chrissy Sexton, Earth.com Staff Writer