A new assessment of shoreline change along the Pacific Northwest coast from the late 1800s to present found that while the majority of beaches are stable or slightly accreting (adding sand), many Oregon beaches have experienced an increase in erosion hazards in recent decades. Since the 1960s, 13 of the 17 beach “littoral cells” – stretches of beach between rocky headlands and major inlets – in Oregon have shifted, either from a pattern of accretion to one of erosion, or to an increased amount of erosion, or they have built up less than in the past.
Some of the hardest hit areas along the coast include the Neskowin littoral cell between Cascade Head and Pacific City, and the Beverly Beach littoral cell between Yaquina Head and Otter Rock, where shoreline change rates have averaged more than one meter of erosion a year since the 1960s. The assessment is part of a series led by the U.S. Geological Survey to study shoreline change in the nation’s coastal regions to more comprehensively monitor coastal erosion and land loss. Peter Ruggiero, an Oregon State University coastal hazards specialist and lead author on the report, said the findings provide baseline data to analyze future impacts of climate change, sea level rise and storms on the Northwest’s shorelines, he added.
“In a general sense, Oregon has faced much more erosion in the short term than has southwest Washington, which has seen more accretion as a result of sediments from the Columbia River and jetties at the mouth of the Columbia and at Gray’s Harbor,” said Ruggiero, an associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The Columbia has less of an influence on Oregon, and many of the state’s beaches have a relatively limited sediment supply,” Ruggiero added. “The buildup and loss of sand on our beaches is a natural process, but one that can be heavily influenced by human behavior and changes in climate.” Continue reading