DUNE GROWTH DUE TO AEOLIAN SEDIMENT TRANSPORT AND THE ROLE OF THE BEACH AND INTERTIDAL ZONE

The development of dunes is characterized by the alternating effects of erosion during storm events and growth during milder conditions. The quantification of dune growth due to aeolian processes has received some attention but uncertainty remains on where the dune sand, which accommodates growing dunes, originates from in the coastal profile. In this paper we hypothesize that sediment eroded from the upper beach is the main sediment supply for aeolian sediment transport governing dune growth. To test this hypothesis we have analyzed morphological profiles collected monthly at three different field sites (Noordwijk, Vlugtenburg and Narrabeen) during several years. No significant erosive trend due to aeolian processes was found at the upper beach at this temporal resolution. We conclude that it is highly unlikely that the main supply for aeolian sediment transport governing dune growth was located at the upper beach. The intertidal zone might be a relevant alternative source of sediment in the cross shore profile.