© D. Oda
Sea level rise will cause drainage problems in low-lying areas due to groundwater inundation, as seen here in the Mapunapuna area, in Honolulu, Hawaii.
Scientists from the University of Hawaii at Manoa (UHM) published a study today in
Nature Climate Change showing that besides marine inundation (flooding), low-lying coastal areas may also be vulnerable to "groundwater inundation," a factor largely unrecognized in earlier predictions on the effects of sea level rise (SLR).
Previous research has predicted that by the end of the century, sea level may rise 1 meter. Kolja Rotzoll, Postdoctoral Researcher at the UHM Water Resources Research Center and Charles Fletcher, UHM Associate Dean, found that the flooded area in urban Honolulu, Hawaii, including groundwater inundation, is more than twice the area of marine inundation alone. Specifically, a 1-meter rise in sea level would inundate 10% of a 1-km wide heavily urbanized area along the shoreline of southern Oahu and 58% of the total flooded area is due to groundwater inundation.
"With groundwater tables near the ground surface, excluding groundwater inundation may underestimate the true threat to coastal communities," said Rotzoll, lead author of the study.
"This research has implications for communities that are assessing options for adapting to SLR. Adapting to marine inundation may require a very different set of options and alternatives than adapting to groundwater inundation," states Fletcher, Principle Investigator on the grant that funded the research.
