Monitoring natural and geo- hazards at cultural heritage sites using Earth observation: the case study of Choirokoitia, Cyprus

Monitoring natural hazards due to climate change and natural hazards at cultural heritage sites facilitates the early recognition of potential risks and enables effective conservation monitoring and planning. Landslides, earthquakes, rock falls, ground subsidence and erosion are the predominant natural hazards in Cyprus, which pose serious disadvantages to cultural heritage sites as well as potential danger to visitors. To identify and monitor natural hazards and environmental displacements Earth observation techniques, such as SAR, can be used in combination with in-situ methods.

The EXCELSIOR H2020 Widespread Teaming project under Grant Agreement No 857510 and the TRIQUETRA project Horizon Europe, Grant Agreement No. 101094818 will study the use of Earth observation techniques for examining cultural heritage sites. The TRIQUETRA project will examine Choirokoitia, Cyprus as a pilot project using these techniques. Choirokoitia is a UNESCO World Heritage Site and is one of the best-preserved Neolithic sites in the Mediterranean. The project will examine the potential risk of rockfall at the Choirokoitia site, as the topology of the site is vulnerable to movements as a result of extreme climate change as well as of daily/seasonal stressing actions. Rockfall poses a significant danger to visitor safety as well as damage to cultural heritage sites.

As well, the Choirokoitia site will be used to detect and analyse natural hazards induced ground deformation based on InSAR ground motion data and field survey techniques for cultural heritage applications. InSAR data, satellite positioning and conventional surveying techniques will be employed to measure micromovements, while other techniques such as UAVs and photogrammetry will be used for documentation purposes and 3D modelling comparisons. In order to identify and monitor natural hazards and their severity, a permanent GNSS station and corner reflector, as well as analysing multitemporal SAR satellite data will be used to estimate the rate of land movement. SAR monitoring provides the opportunity to identify deformation phenomena resulting from natural hazards for monitoring and assessing potential hazards using remote sensing techniques to measure and document the extent of change caused by the natural and/or geo-hazards. PSI (Persistent Scatterer Interferometry) analysis can be used in the wider area to determine potential displacements.

The study is expected to lead towards the systematic monitoring of geohazards, and more specifically those of ground deformation and rock falls to facilitate the early recognition of potential risks and enable effective conservation monitoring and planning. The methodology can be used to monitor cultural heritage sites worldwide which are vulnerable to natural hazards.