Beach nourishment and foredune restoration: practices and constraints along the Venetian shoreline, Italy

Artificial beach nourishment is commonly practiced along the North Adriatic coast of Italy to fight beach erosion. About 10 million m3 of sand has been placed along 45 km of coast in 10 years. The strong wind regime and the need to protect coastal habitat have drawn attention to problems associated with aeolian transport and dune reconstruction. This study analyses three nourished sites, where morphological and sedimentological data were gathered along complete beach/dune profiles. The beach/dune sediment budget over a period of 2, 6 and 10 years after the interventions and the elevation and distance of the reconstructed dunes from the shoreline were examined and compared with a natural control area. A grain size suitability evaluation was carried out, together with a verification of the effects of grain size selection in transport from the beach to the dune. The study enabled evaluation of the potential for nourishment practices to reconstruct and restore the beach/dune system. The renewed sediment availability yielded different results in term of dune supply, ranging from the total lack of dune accretion to the spontaneous formation of embryo foredunes. Dune changes do not depend on sediment used for fill, because the relatively fine grain size does not limit aeolian transport. The beach management practices (fences, raking etc.) seem to be critical, together with shoreline orientation and the consequent aeolian transport potential. In many cases, the practices are not suitable and should be redirected to achieve a satisfactory compromise between environmental protection and recreational use.