The significance of geometry in natural embayments has been at the center of attention in only a few coastal studies and needs to be analyzed in detail. The present paper focuses on 1) the significance of planform geometry and orientation of embayed beaches and headlands relative to incident wave energy; 2) Depth of closure, whether located inside or outside bays; 3) cross-shore sediment size variation in embayments. Studies were performed in 23 pocket beaches of Elba Island (Italy). The results indicate that exposure to incident wave energy does not determine the orientation of pocket beaches. Regardless of the angle of wave incidence, there is a strong correlation between the orientation of pocket beaches and the alignment of headlands, indicating a static equilibrium. The location of Depth of closure in the embayments shows that bed activity is fully captured inside seven bays, while nine bays are partially closed and seven are completely open. Sediment size data, available for five embayments, suggest an offshore-coarsening trend starting where the depth increase is counteracted by higher exposure to waves. A conceptual model is proposed for this process.

The significance of sediment delivered via storm-associated stream discharge in altering sediment characteristics, beach form, and volume is evaluated on pocket beaches with different basin characteristics and wave exposures. The focus is on changes on three beaches on Elba Island, Italy caused by a flood event in September 2002 that had an estimated recurrence interval of 200years. Beach profiles and foreshore sediment samples were gathered in 1999 and 2000 to identify pre-storm characteristics, in September 2002 to reveal the immediate effects of the storm, and in 2003 and 2004 to reveal post-storm recovery.

Cipriani, L.E., Pranzini, E. Rosas, V. and Wetzel, L. 2011. Landuse changes and erosion of pocket beaches in Elba Island (Tuscany, Italy). Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal symposium), 1774 - 1778. Szczecin, Poland, ISSN 0749-0208. The evolution trend of 17 natural pocket beaches (Elba Island, Italy) under "regular" sediment input was studied over a 24 years (average) preceding a 200 year return time flood. Thirteen beaches were found to be eroding, and only two to be naturally accreting, whereas two increased their surface as a consequence of beach nourishment projects carried in the 1990s. Beach erosion in Elba affects beaches independently from their size and wave energy and appears to be a regional process. Coastal structures are mostly absent from these bays (except for Marina di Campo, where a marina breakwater situated on one headland induced beach rotation). Factors triggering coastal erosion were investigated among land use changes that occurred in the Island after World War II: the development of tourism in Elba Island reduced agricultural activities, increased forest coverage and expanded residential areas. During the past 40 years approximately 3200 hectares of agricultural areas were lost; this corresponds to circa 72% of the original area, diminishing the surface susceptible to soil erosion and thus sedimentary input to the coast.

A megaflood, with an estimated recurrence time of approximately 200 yr, affected the Elba Island in September, 2002. In several pocket beaches, active and reactivated creeks discharged a huge volume of unsorted sediments to the coast. Since the morphological and sedimentological conditions of one of these bays (Gulf of Procchio) was known due to topographic and sedimentologic studies performed in 1999, the impact of this event was easily evaluated through a survey performed a few days after the flood. The main beach responses were the formation of ring deltas, the increase of the fine fraction in the nearshore sediments and the coarsening of those in the swash zone.A further survey in 2004 allowed monitoring the recovery of the beach, which is still returning to the pre-event conditions, at a slow rate. Although only the widest delta among those formed is still identifiable on the shoreline, and in spite of the nearshore sediments having lost all the fines, gravel and cobbles are still present from the step to the berm crest in the sectors adjacent to the old outlets and gravel is moving alongshore. The erosion that affected some pocket beaches at Elba during the second half of the 20th century, firstly attributed to the agriculture abandonment and to the consequent forest recovering, now has a new or additional cause: the return of the bay to pre-flood conditions within cycles of catastrophic accretion followed by mild erosion.