Mediterranean UNESCO World Heritage at risk from coastal flooding and erosion due to sea-level rise

Abstract

UNESCO World Heritage sites (WHS) located in coastal areas are increasingly at risk from coastal hazards due to sea-level rise. In this study, we assess Mediterranean cultural WHS at risk from coastal flooding and erosion under four sea-level rise scenarios until 2100. Based on the analysis of spatially explicit WHS data, we develop an index-based approach that allows for ranking WHS at risk from both coastal hazards. Here we show that of 49 cultural WHS located in low-lying coastal areas of the Mediterranean, 37 are at risk from a 100-year flood and 42 from coastal erosion, already today. Until 2100, flood risk may increase by 50% and erosion risk by 13% across the region, with considerably higher increases at individual WHS. Our results provide a first-order assessment of where adaptation is most urgently needed and can support policymakers in steering local-scale research to devise suitable adaptation strategies for each WHS.

Sea Level Rise Scenario for 2100 A.D. in the Heritage Site of Pyrgi (Santa Severa, Italy)

“…Due to the potential significant impacts on both the coast and the heritage sites of the Temple of Pyrgi and the Santa Severa Castle with a beach retreat up to ~25 m, the expected scenario shown in this study can support adaptation planning at different time scales, in agreement with the Protocol on Integrated Coastal Zone Management (ICZM) in the Mediterranean. Our results details previous studies for the Italian [19,30,31,32,33,34,35] and the Mediterranean [36,37] regions and can raise awareness of policymakers and heritage managers, highlighting the need for adaptation actions to protect Pyrgi from marine flooding and erosion under the current conditions and for the expected sea level rise scenarios. To this regard, we remark that [38] estimated a mean coastal erosion at a rate of 3.3 cm/year since the last 2.500 years although the retreat of the soft cliffs characterizing the Pyrgi coastline is occurring mostly during high energy marine events.…”

Implementing a Modern E-Learning Strategy in an Interdisciplinary Environment—Empowering UNESCO Stakeholders to Use Earth Observation

“…As shown above, various applications such as for example on natural disasters and natural hazards, like flooding already available to facilitate the work of UNESCO-site stakeholders [21,22]. The potential negative impacts of the predicted climate change will probably increase the necessity of an operational monitoring [41]. Applications on radar satellites to monitor movements of single buildings or small-scale unites in a range of cm or even mm will probably be introduced in the future [18,19].…”

Climate Change Adaptation in Natural World Heritage Sites: A Triage Approach

“…That process for prioritizing investment of scarce resources is implicitly applied on a daily basis by managers and policymakers, but its inherent logic (i.e., specific triage application) is most often implicit [38]. For example, Reimann et al [39] followed a triage approach to offer an index that allows ranking WH at risk from coastal hazards and found it successful. Krosby et al [40] used large temperature gradients, high canopy cover, large relative width, low exposure to solar radiation, and low levels of human modification to calculate a riparian climate-corridor index that results in triage-based risk evaluations ranging in scale from local watersheds to the entire Pacific Northwestern US.…”

“…This in turn, will enable the management team to prioritize responses against criteria, providing a basis for action that can be monitored and reviewed. By explicitly acknowledging that scenarios and decisions are based in triage, the manager will be able to evaluate tradeoffs and provide transparency of decision-making [39]. broad challenges that should guide such awareness: (1) conservation in a changing system requires a focus on the values and not the state of the system; (2) local and regional management should be nested in more coarse-scale governance structures; and (3) the management approach must be sufficiently adaptable that it is able to deal with uncertainty and nonlinearities.…”

“…This in turn, will enable the management team to prioritize responses against criteria, providing a basis for action that can be monitored and reviewed. By explicitly acknowledging that scenarios and decisions are based in triage, the manager will be able to evaluate tradeoffs and provide transparency of decision-making [39]. [38].…”