Embryo dune development on a large actively accreting macrotidal beach: Calais, North Sea coast of France
Résumé
Sediment budget data from an 18-month topographic survey were analysed with data from brief experiments on wind parameters, beach moisture contents, bedforms and sand mobili- zation in order to monitor conditions and patterns of embryo dune development over a flat 150–1000 m wide accreting upper beach. The surface conditions over the upper beach locally affect aeolian transport, but net dune development over time depends on sustained strong winds and their orientation. Incoming marine sand supplied by storms and onshore winds is reorganized by the dominant offshore to longshore winds into elongated embryo dunes over this upper beach, imprinting a regional morphology of long-term longshore dune ridge development.