Climate change - induced hazards on touristic island beaches: Cyprus, Eastern Mediterranean

Abstract

This contribution presents an assessment at a regional (island) scale of the beach erosion due to storm events under Climate Change. The approach adopted to assess beach erosion at the island scale consisted of three modules. First, the location, dimensions and other attributes of the Cypriot beaches were recorded on the basis of widely-available satellite imagery. Secondly, sea levels and waves were modeled along the coast under different climatic scenarios and dates in the 21st century. Finally, using these projections beach retreat due to the relative mean sea level rise (RSLR) and extreme sea levels (ESLs) was estimated using ensembles of analytical and numerical cross-shore morphodynamic models, respectively. Extreme sea levels (ESLs) were projected to (a) increase by up to 60% in 2100 from their baseline (2000) levels, and (b) vary along the coast, with the highest ESLs (and corresponding waves) projected for the southern and western coasts. The mostly narrow Cypriot beaches (91% recorded maximum widths of < 50 m) showed increased exposure to erosion. In 2100, about 47% and 72% (based on the median model estimates) of the 241 unprotected Cypriot beaches will be permanently eroded, due to mean sea level rise (SLR), to 50% of their present maximum width, depending on the scenario. In addition to the long-term erosion due to SLR, severe storm erosion is projected by 2050 even under the RCP4.5 scenario; the 100-year extreme sea level event (ESL100) may overwhelm (at least temporarily) 49% of the currently unprotected Cypriot beaches without effective adaptation responses, with the most exposed beaches located along the northern coast. As the beach carrying capacity and hedonic value will be severely compromised, effective adaptation policies and technical measures will be urgently required.

Coastal flood and erosion risk under climate change: An overview of policies and legislation in Greece and Cyprus

“…A recent, Cyprusscaled study has also found that the baseline ( 2000) ESL100, which ranged between 0.8 and 1.3 m above the mean sea level (MSL), will increase to up to 2.05 m by 2100 (Monioudi et al, 2023). Regarding the waves, these have been projected not to increase, or even slightly decrease during in the 21 st century (Velegrakis et al, 2023a;Monioudi et al, 2023). Although the above hazard increases may appear moderate, their impacts on the island beaches can be devastating due to their generally small dimensions; about 59 % of Aegean island beaches have had recorded maximum 'dry' widths -BMWs of < 20 m and 92 % < 50 m, whereas, in Cyprus, almost 42 % of beaches were recorded having BMWs of < 20 m and 91 % < 50 m. Consequently, both the long-and short-term beach erosion can be very impactful to the backshore human and natural environment.…”

“…By 2100, the increases of ESLs100 relative to the baseline will be close to 0.9 m for some Greek island and Cyprian coasts under RCP8.5, even under a median ice-melt scenario (Figure 2), whereas higher ESLs100 increases are projected under the high-end scenario. A recent, Cyprusscaled study has also found that the baseline ( 2000) ESL100, which ranged between 0.8 and 1.3 m above the mean sea level (MSL), will increase to up to 2.05 m by 2100 (Monioudi et al, 2023). Regarding the waves, these have been projected not to increase, or even slightly decrease during in the 21 st century (Velegrakis et al, 2023a;Monioudi et al, 2023).…”

“…A RSLR of 0.7 m can drive beach retreat/drowning of up to 68 % of the Aegean archipelago beaches, affecting back shore assets at about 1730 beaches; under extreme sea levels, an extreme sea level of 1.1 m has been projected to result in short-term full erosion of up to 88 % of all beaches affecting backshore assets in at 2270 beaches (Monioudi et al, 2017). For Cyprus, on the basis of the median projected erosion, a RSLR of about 0.8 m about 30 % of all beaches will be fully eroded, whereas by 2100 up 70 % of all beaches will under full short-term erosion by 2100 (Monioudi et al, 2023).…”

“…These are backed by small drainage basins of high relief with intermittent water and sediment flows (which is many cases are now choked by dams), and fronted by relatively narrow (inner) continental shelves with relatively high seabed slopes that allow limited wave attenuation and promote net offshore sediment transport. The basement geological formations also control beach development/evolution; for example, Cyprus beaches associated with the geological formations of the Troodos and Kyreneia terranes are generally narrower than the rest of the Cyprus beaches (Monioudi et al 2023). Concerning the latter beachrocks, which are quite prevalent in Eastern Mediterranean, can affect beach morphodynamics by: 'locking' the beach profile, modifying the nearshore hydrodynamics, changing the porous character of the beach and, thus, its response to wave forcing; and differential seabed erosion at the margins of the beachrock outcrops that can alter significantly the long-and, particularly, the cross-shore sediment transport (Vousdoukas et al, 2007).…”

“…The objective of this short contribution is to provide a brief overview of the drivers and impacts of beach erosion focusing at the Greek islands and Cyprus), the beaches of which are vulnerable to erosion and major tourist destinations (e.g. Monioudi et al, 2017;2023).…”