Assessment of island beach erosion due to sea level rise: The case of the Aegean Archipelago (Eastern Mediterranean)

The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean Archipelago (Greece), a critical resource for both the local and national economy; and (b) provide a rapid assessment of the impacts of the long- term and episodic sea level rise (SLR), under different scenarios. Spatial information and other attributes (e.g. presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the Archipelago were obtained on the basis of remote-sensed images available in the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing and SLR scenarios were estimated, using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically-derived estimations of wave run up-induced flooding, were then compared with the recorded maximum beach widths, to provide ranges of retreat/erosion and flooding at the Archipelago scale. The spatial information shows that the Aegean beaches may be particularly vulnerable to mean (MSLR) and episodic SLRs due to: (i) their narrow widths (about 59 % of the beaches have maximum widths < 20 m); (ii) their limited terrestrial sediment supply; (iii) the substantial coastal development and (iv) limited existing coastal protection. Modeling results indeed project severe impacts under MSLR and storm surges, which by 2100 could be devastating. For example, under MSLR of 0.5 m (RCP4.5), a storm surge of 0.6 m is projected to result in complete erosion of between 31 and 88 % of all beaches (29 - 87 % of beaches currently fronting coastal infrastructure and assets), at least temporarily. It appears that, in addition to the significant effort and financial resources required to protect/maintain the critical economic resource of the Aegean Archipelago, appropriate coastal ‘set-back zone’ policies should also be adopted and implemented.

MONIOUDI Isavella;  VELEGRAKIS Adonis;  CHATZIPAVLIS Antonios;  RIGOS Anastasios;  KARAMBAS Theophanis;  VOUSDOUKAS Michail;  HASIOTIS Thomas;  KOUKOUROUVLI Nikoletta;  PEDUZZI Pascal;  MANOUTSOGLOU Evangelia;  POULOS Serafim;  COLLINS Michael B.; 

2017-07-07

COPERNICUS GESELLSCHAFT MBH

JRC102987

1561-8633,   

http://www.nat-hazards-earth-syst-sci-discuss.net/nhess-2016-336/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC102987,   

10.5194/nhess-2016-336,