Morphodynamics of a mediterranean microtidal wave-dominated beach: Forms, processes and insights for coastal management

Abstract

The aim of this study is to present a new morphodynamic map (1:10,000 scale) of a wavedominated sector of a Mediterranean ria-type coast (NE Sardinia, Italy). The area has been studied since 1995 with respect to its geomorphological and sedimentological processes. Our map is produced using topographic-bathymetric, textural and compositional data collected during different surveys conducted from 1995 to 2014. The Main Map shows forms, processes and deposits of the coastal belt, as well as the main geological outcrops, structural elements and the areal distribution of seagrass, mainly Posidonia oceanica (L.) Delile and Caulerpa prolifera (Forsskaal) Lamouroux. The map is useful for beach management purposes. It is noteworthy that the role of P. oceanica in the littoral area is twofold: (1) acts as a barrier to siliciclastic material from the backshore; and (2) a producer of biogenic/bioclastic sediment. Based on side-scan sonar images, the P. oceanica meadow appears to be threatened by direct mechanical damage caused by boat anchoring and mooring activities. The human impact on dune habitats has also been recognized and is related to pedestrian and vehicular transit, boat storage and infrastructure for bathing.