Land Loss Rates: Louisiana Coastal Plain

Abstract

Land loss mapping and rate curve development for 62 quadrangles in the Louisiana Coastal Plain show that land loss rates vary significantly throughout coastal Louisiana. Differences in land loss rates among individual quadrangles are a function of the geologic setting, and the factors that contribute to land loss. Of the 62 quadrangles mapped, 16 show an increase in the land loss rate, 36 show a decrease, and 10 remained approximately the same. On a regional scale, the land loss rate for the entire Louisiana Coastal Plain has decreased from an average yearly rate of 41.88 square miles for the 1956-58 to 1974 period to 30.71 square miles for the 1974 to 1983 period. The data generated during the land loss study is being combined with engineering geology, geomorphic, and subsidence data to determine the causes for land loss in site specific areas of the Louisiana coast. It will also be used to identify areas of maximum and minimum land loss so that mitigation efforts can be planned in areas where the potential for significant reduction in land loss is greatest.