Impacts of sea level rise on the cultural heritage of oceanic islands: Modeling twenty-first century scenarios in the Canary archipelago

Oceanic islands constitute 0.05% of emerged land masses but account for 2% of UNESCO World Heritage Sites. Physical constraints have determined that the history of these remote territories is marked by globally unique forms of colonization and human cultures. A significant part of this heritage, located in coastal areas, is threatened by the mean sea level rise (SLR) due to anthropogenic climate change. This paper presents a regional approach to the risk estimation of SLR in the cultural heritage of oceanic islands, taking the Canary Islands (Spain) as an example. The Canary Islands is one of the most prominent oceanic archipelagos in the world (similar to 1500 km of coastline), where cultural heritage, preferentially located in the coastal areas (up to 50% in the first 1 km), nicely represents the two major stages of human occupation of islands (aboriginal and European). Through process-based modeling, high resolution flood maps were obtained for 20 climate scenarios and complete coverage of the archipelago. These maps were combined with detailed planimetries of 343 officially designated cultural heritage sites, applying damage functions to relate flood depth with the type of construction and the historical period. The results indicate potential damage to 55 cultural heritage sites of the Canary Islands which could be significant in 15 of them. For these cases, it is recommended to study specific adaptation measures aimed at mitigating the flood risk, such as moving the heritage assets away from the hazard areas or reinforcing and protecting the structures to reduce their vulnerability.