Morphometric Analysis and Classification of the Embayed Beaches on the Southern Coast of Sardinia Island (Western Mediterranean Sea)

Embayed beaches are widespread along the world coastlines. They are characterized by a curved shape and by headlands that bordering them laterally. Morphometric classification of beaches can provide information on the relationships among factors that control their dynamics (e.g. incident waves, laterally constrains, sheltered beach area etc.). The aim of this work is to provide for the first time an analysis and a morphometric classification of embayed beaches on the Southern coast of Sardinia Island, Western Mediterranean Sea. GIS tools, applied on aerial orthophotos, were used to measure the morphometric parameters of each beach. The classification is carried out through the Embayment Morphometric Parameter (γe). Totally, 79 beaches along the coastal stretch studied are identified and mapped. The attribution of the embayment class for each beach is performed through a K-means cluster analysis of the (γe) values. Based on the (γe) values we grouped beaches into 4 classes. The embayment degree increases from Class 1 to Class 4. Within Class 1 are all those beaches characterized by a low embayment degree with (γe) < 0.56 (16%). Within Class 2, beaches begin to have a moderate embayment degree with (γe) values between 0.59-0.81 (40%), while Class 3 is characterized by (γe) values between 0.82-1.08 (32%). Class 2 and 3 are the most common classes. The highest embayment degrees are associated with Class 4 with (γe) > 1.12 (12%). More than 40% of the monitored beaches are classified as embayed or high embayed, this reveals that in this coastal stretch the effects of boundaries and the interaction among waves and morphological features can have a great importance on the dynamics and morphology of the beaches. All this information can also be useful for coastal managers.