O‘ahu’s sandy beaches are at risk. New research from the Coastal Research Collaborative (CRC) at the University of Hawai‘i (UH) at Mānoa determined that 81% of O‘ahu’s coastline could experience erosion by 2100, with 40% of this loss happening by 2030.
O‘ahu’s sandy beaches are at risk. New research from the Coastal Research Collaborative (CRC) at the University of Hawai‘i (UH) at Mānoa determined that 81% of O‘ahu’s coastline could experience erosion by 2100, with 40% of this loss happening by 2030. Importantly, these forecasts of shoreline erosion are more extreme than previous studies indicated for Oʻahu. The study was published recently in Scientific Reports.
“Our findings reiterate the already observed threat of coastal erosion as a hazard to sea level rise in Hawai’i,” said Richelle Moskvichev, geospatial modeler at the CRC in the UH Mānoa School of Ocean and Earth Science and Technology and lead author of the study. “In rapidly eroding areas, communities may see damage to roads, homes, or underground infrastructure. Shorelines along the north shore and east side of Oʻahu that are backed with hard-armoring, such as seawalls, could experience total beach loss.”
To create erosion predictions, the team of researchers used a computer model that incorporates about thirty years of satellite imagery, as well as aerial and drone imagery. The new model also directly accounts for the seasonal movement of sand. For example, when large swells arrive in the winter on Oʻahu’s north shore, sand is transported from one part of the beach to another.
Given prior modeling efforts, the team’s own survey observations, and anecdotal evidence from residents, the researchers expected to see erosion predicted for many sandy beaches around Oʻahu.
Read more at University of Hawaii at Manoa
Image: A residence with a small sandy beach flanked with temporary hardening structures, in Punalu‘u, O’ahu. (Credit: Shellie Habel, UH Manoa- SOEST)
