Coastal challengesHarnessing Wave Power to Rebuild Islands

Many island nations, including the Maldives in the Indian Ocean, are facing an existential threat as a result of a rising sea level induced by global climate change. A group of MIT researchers led by Skylar Tibbits, an associate professor of design research in the Department of Architecture, is testing ways of harnessing nature’s own forces to help maintain and rebuild threatened islands and coastlines.

Some 40 percent of the world’s population lives in coastal areas which are threated by sea level rise over the coming decades, yet there are few proven measures for countering the threat. Some suggest building barrier walls, dredging coastlines to rebuild beaches, or building floating cities to escape the inevitable, but the search for better approaches continues.

The MIT group was invited by Invena, a group in the Maldives who had seen the researchers’ work on self-assembly and self-organization and wanted to collaborate on solutions to address sea-level rise. The resulting project has now shown promising initial results, with a foot and a half of localized sand accumulation deposited in just four months. MIT News’s David L. Chandler asked Tibbits to describe the new approach and its potential.

David L. Chandler: People have been trying to modify and control the movement of sand for centuries. What was the inspiration for this new and different approach to rebuilding beaches and shorelines?
Skylar Tibbits: When we first visited the Maldives, we were taken to a local sandbar that had just formed. It was incredible to see the size of the sandbar, about 100 meters long and 20 meters wide, and the quantity of sand, over 1 meter deep, that was built completely on its own, in just a matter of months. We came to understand that these sandbars appear and disappear at different times of the year based on the forces of the ocean and underwater bathymetry. Local historians told us about how they would collaborate with the ocean, growing vegetation to expand their islands or morph their shape. These natural and collaborative approaches to growing land mass through sand self-organization came in stark contrast to the human dredging of sand from the deep ocean, which is also used for island reclamation. In the same amount of time that it takes to dredge an island, which takes months, we watched three different sandbars form themselves, through satellite imagery.