We’ve all heard about the threat that rising seawater levels pose to coastal communities as a result of climate change. But what many never considered was the impact this flooding would have on the groundwater levels. Scientists from the University of Hawaii at Manoa published a study showing that as the planet continues to warm, not only is seawater a threat, but flooding from groundwater sources could be just as big, if not a bigger threat to coastal communities.
Scientists conducted their research along the southern shoreline of Oahu, Hawaii, and found that with a 3-foot rise in sea levels — which scientists predict could happen by the end of the century – 10-percent of the studied area would be inundated by water. But what’s surprising about their findings is that 58 percent of this flooding would be caused by groundwater flooding, rather than seawater alone.
What these findings mean is that groundwater tables that lie near the surface must be taken into account as coastal cities prepare their plans to cope with rising sea levels. “Finding that the inundated areas double when including groundwater inundation in coastal flooding scenarios will certainly be a surprise for everyone assessing the effects of sea level rise without considering the local groundwater table,” says Kolja Rotzoll, one of the lead researchers on the project.