Short-Term Changes in Beach Morphology on Louisiana Coast

L. D. Nakashima

A study of the short-term response of seven shoreline segments between the Sabine River and Sandy Point is based on data from a three-year coastal erosion monitoring project. Seventy-eight beach-profile transects were surveyed quarterly between December 1985 and March 1988 to determine their patterns and rates of shoreline change. Efforts were made to characterize straight and curved shorelines as well as those that have been artificially stabilized.

Systematic variations in shoreline change were not evident within each shoreline segment. The average rate of beach erosion is about 2 m/year along the coast, but the rate of coastal-structure erosion is fastest, exceeding 5 m/year. The Plaquemines barrier shoreline at its eastern end is retreating the fastest of all segments (2.5 m/year), and is also characterized by the highest volumetric losses, the least relief, and the narrowest beaches. The western chenier plain is eroding at 2 m/year, but volumetric losses are substantially reduced through backshore deposition from eolian activity.

AAPG Search and Discovery Article #91036©1988 GCAGS and SEPM Gulf Coast Section Meeting; New Orleans, Louisiana, 19-21 October 1988.