Louisiana's Barrier Islands: An Evaluation of their Geological Evolution, Morphodynamics and Rapid Deterioration

Abstract

Louisiana leads the United States of America, and likely the world, in coastal erosion and wetland loss. Landward translation of the barrier islands fronting the bays and estuaries of Louisiana exceeds 20 m/yr. Over the last century or so, the subaerial mass of many of these islands has been reduced by between 40 and 75 percent. Recent findings indicate that entire barriers will likely be transformed into shoals over the next decade or so. Ongoing numerical model studies indicate that this will result in significant increases in wave energy in the bays and estuaries, likely increasing rates of fringing marsh deterioration. Considering that Louisiana contains 40 percent of the Nation's coastal and estuarine wetlands in the 48 conterminous states, and that 80 percent of the Nation's total loss of wetlands has occurred in Louisiana, the problem transcends the State boundaries and has become one of National concern.