MODELING BARRIER ISLAND RESPONSE TO SEA-LEVEL RISE IN THE OUTER BANKS, NORTH CAROLINA

摘要

An 8500-year Holocene simulation developed in GEOMBEST provides a possible scenario to explain the evolution of barrier coast between Rodanthe and Cape Hatteias, NC. Sensitivity analyses suggest that in the Outer Banks, the rate of sea4evel rise is the most important factor in determining how barrier islands evolve. The Holocene simulation provides a basis for future simulations, which suggest that if sea level rises up to 0,88 m by AD 2100, as predicted by the highest estimates of the Intergovernmental Panel on Climate Change, the barrier in the study area may migrate on the order of 2,5 times more rapidly than at present If sea level rises beyond IPCC predictions to reach 1 4-1,9 m above modem sea level by AD 2100, model results suggest that barrier islands in the Outer Banks may become vulnerable to threshold collapse, disintegrating during storm events, by the end of the next century Consistent with sensitivity analyses, additional simulations indicate that anthropogenic activities, such as increasing the rate of sediment supply through beach nourishment, will only slightly affect barrier island migration rates and barrier island vulnerability to collapse.