SHORELINE VARIABILITY OF BARCELONA CITY BEACHES IN RESPONSE TO STORMS AND ARTIFICIAL NOURISHMENT (2001-2003)

摘要

The morphological behaviour of three of Barcelona City beaches (Bogatell, Nova Icaria and La Barceloneta) in response to storms and to an artificial nourishment was studied from November 2001 to December 2003 by means of an Argus video system (Holman et al., 1993) used to obtain time-series of shoreline position and emerged beach area. Major shoreline fluctuations were due to beach rotation caused by alongshore sediment transport during storms. La Barceloneta and Bogatell beaches presented morphological responses depending on their orientation with respect to the storm direction. However, shoreline evolution in Nova Icaria was strongly affected by defence structures. Although the artificial nourishment caused strong beach accretion and increased the beach surface for some months, the erosive processes prevailed causing, a year and a half later, beach areas equivalent or smaller than those before nourishment was implemented. Significant sediment exchange has been detected between Bogatell and Nova Icaria beaches bypassing the submerged breakwater.