The consequences of a future eustatic sea-level rise on the deltaic coasts of Inner Thermaikos Gulf (Aegean Sea) and Kyparissiakos Gulf (Ionian Sea), Greece

The spatial consequences of future sea-level rise upon the coastal plains of Greece are examined; in particular, those related to the formation and evolution of the river-deltas. For this reason, the fluvially-dominated deltas of the Axios and Aliakmon rivers of Inner Thermaikos Gulf (NW Aegean Sea) together with the wave-dominated delta of the Alfios River (Kyparissiakos Gulf, Ionian Sea), are investigated. Coastal changes are quantified due to the combined effects of the processes of inundation, because of the increased sea level, and subsequent coastal erosion, due to increased exposure to wave action. Predictions of responses to future sea-level rise, of 0.5 to 1 m, are made. In the case of the deltaic coast of the Alfios, exposed to high waves and protected by dune fields, shoreline retreat of up to 700 m is predicted. The low-lying bird-foot type deltas of the Axios and Aliakmon are expected to retreat by more than 2 km. Furthermore, coastline retreat in the case of Alfios is related primarily to the process of shore zone erosion; in the case of the Axios and Aliakmon, it is related to the process of inundation.