Hybrid coastal structures combine benefits of dunes, artificial barriers

Image: Yuan-Chi Lee, Research Communications

Nearly half the world’s population lives within 62 miles (100 kilometers) of a coastline. This means exposure to the increasing risk of flooding and destruction in light of rising sea levels, eroding coastlines, and more frequent storms like hurricanes that bring storm surges and devastating waves to the coast. Hurricanes Katrina, Laura, Ike, Dorian and many more in the recent past are prime examples. It is imperative to find new, innovative ways to reduce the risk coastal communities and infrastructure face.

Jens Figlus, associate professor in the Department of Ocean Engineering at Texas A&M University at Galveston, and a team of researchers are safeguarding coastal communities through better designed hybrid coastal structures. These structures combine the benefits of coastal sand dunes with those offered by traditional, human-made structures, like seawalls, sea dikes and rubble mounds, to elevate their effectiveness and resilience.

In an international endeavor to strengthen coasts around the globe, the team is combining physical model testing with numerical simulations to outline the physical properties to achieve the best defense against flooding. This work, inspired by natural sand dunes, will bridge the gap between research and application – allowing such structures to be utilized around the globe.

Working with the Coastal Engineering Lab, the Center of Texas Beaches and Shores, and researchers from other institutions, such as the Stevens Institute of Technology and Delft University of Technology in The Netherlands, Figlus is testing how the combination of sand dunes and hard structures can best weather a storm.

“The idea is that we’re trying to make something look and have vegetation ecosystems like a natural dune, but in its core, hidden underneath the sand layers, would be a hard structure. The combination of sand cover and hard structure is intended to do the job of reducing the risk of flooding, inundation and destruction behind it in the event of a big storm surge and massive wave attack – like during Hurricane Ike, but at the same time provide the aesthetic appeal and ecosystem services like a natural dune under normal conditions,” Figlus said.

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