Adaptive Conservation Strategies for Butrint's In-Situ Mosaics: Addressing Climate Change Impacts on World Heritage Sites

In a still unspoilt corner of Albania's coast, the WHS of Butrint is a unique combination of nature and art surrounded by a lake connected by a canal to the sea. The abundance of spring waters with healing properties decreed the success of its foundation, while the later difficulties in defending it from flooding increasingly depopulated it until it was abandoned. Today, the site, one of the most significant in the Mediterranean basin for high values of nature and culture in an environmental context of rare integrity, is also among the sites most threatened by climate change. The scenario predicted by the 2021 IPCC report reveals that the future sea levels in the Ionian Sea will affect the ancient city of Butrint, which will be submerged within decades. Sea level rise in coastal regions of the Mediterranean could reach peaks of 2.2 metres by 2100 in the extreme scenario projection. For the coasts of the Ionian Sea in the region of Corfu and Butrint, the worst-case scenario forecasts a rise in sea level of between 1.6 and 1.8 metres by 2100. Some of its monuments are already permanently or periodically waterlogged. The present study constitutes one piece of a broader doctoral research programme and focuses on defining conservation strategies for the valuable mosaics in situ, in adherence to the approach of preserving mosaic floors in situ. The different environmental conditions of the various mosaics are analysed according to their current conditions and predicted level of submersion risk. Beyond a historical and typological framework of execution, the construction characteristics and the types of tesserae used are described. The study connects the chemical-mineralogical characterization of the marbles and materials used with the most significant chemical-physical environmental parameters to assess the vulnerability level according to the environmental variations. The variation of the saline solution content in the water that permanently or periodically floods some mosaics is analysed as a key factor affecting the on-site conservation of the mosaics. The information gathered from the archaeological study and documentation on previous work allows us to assess the characteristics of the constituent materials, given that the mosaics are currently covered by a protective layer that prevents them from being inspected. Furthermore, the archaeologists' information about their value and significance is essential to support a future conservation plan that links the assessment of the risk of loss with the relevance of the artefacts. A method for sustainable adaptations based on an innovative strategy of environmental and water parameter monitoring is outlined in order to intervene promptly to mitigate climate change decay factors.