A study by University of Hawai‘i researchers has found a third of the state’s shorelines are vulnerable to coastal hazards as the waves and storms that hit the islands become intensified by the growing impacts of sea level rise.
Published in the journal Ocean and Coastal Management, the study examined the shorelines of seven of the eight main Hawaii islands and determined their vulnerability to coastal hazards, ranking each area from low to high risk. Researchers found that 34 percent of Hawai‘i is moderately to highly vulnerable, with shores on Maui, O‘ahu, and Kaua‘i at highest risk.
High-risk zones on O‘ahu include the North Shore from Hale‘iwa to Kahuku, which is exposed to high wave energy, and Ewa Beach, which has low elevation, little reef protection or natural habitat and greater vulnerability to sea level rise. Other areas at risk on O‘ahu include stretches of Kailua, Waimānalo, and Wai‘anae.
Primary author Yaprak Onat from the Department of Ocean Resources and Engineering (ORE) accounted for a range of factors in determining coastal hazard exposure, including topography, underwater landscape, erosion, wave energy, vulnerability to surge and sea level rise. Onat also factored in the effects of natural coastal habitats, defensive structures like sea walls and revetments, plus human activities.