Theoretical and measured aeolian sand transport on a barrier island, Louisiana, USA

Over the past 100 yr, the Isles Dernieres, a low lying barrier island chain along the coast of central Louisiana, has undergone more than 1km of northward beach face retreat within the loss of 70% of its surface area. The erosion results from a long term relative sea level rise coupled with day to day wind and wave action that ultimately favours erosion over deposition. The theoretical estimate of 1.28 m3 m-1 for the rate of sand transport by the northerly wind compares well with the measured backshore erosion rate of 1.26m3 m-1, which was determined by comparing beach profiles from the start and end of the period of northerly winds. The theoretical estimate of 0.04m3 m-1 for the rate of sand transport by the southerly wind, however, is notably less than the measured rate of 0.45m3 m-1. -from Authors