Erosion of the beaches of Crete

Tuesday, 16 December 2014
Vassilios Skanavis1,2, Nikos Kalligeris1,2, Nikos Maravelakis2, Spyros Foteinis2, Giorgos Sartzetakis2, Kostas Papadogiannis2 and Costas Synolakis1,2, (1)University of Southern California, Los Angeles, CA, United States, (2)Technical University of Crete, Environmental Engineering, Chania, Greece
The coastlines of Greece face a substantial erosion problem with some shoreline retreating at rates up to 1m/year. This problem remains largely unrecognized for quantitative measurements of shoreline retreat rates are scarce, while coastal wave measurements for extended period of time are entirely non existent. Most if not all coastal engineering studies rely on SMB type forecasts. Worse, structures are still designed with simple laboratory models that purport to even model coastal erosion, without the benefit of any numerical simulations. 

As a result, in some areas, the structures have accelerated the erosion in adjacent beaches. We present the first ever coastal wave measurements in shallow waters in Greece. From December 2010 to April 2014, three AWACs - instruments that measure wave heights, directions and three dimensional velocity profiles were deployed in 20-25m water depths in the Bay of Chanea, Crete. The measurements revealed waves higher than expected from simple forecasting models. We also present estimates of coastline retreat for the Bay of Chanea and other regions in Crete.