PSI - Issue 64

Luigi Petti et al. / Procedia Structural Integrity 64 (2024) 629–636 631 Petti L., Zuchtriegel G., Lupo C., Calvanese V. & De Gaetano C.M. / Structural Integrity Procedia 00 (2019) 000 – 000 3

Considering the size, complexity and nature of the ancient city of Pompeii, especially in this area of high natural hazards, it is necessary to define an effective and efficient approach to implement surveillance, maintenance and monitoring activities, as well as to fight the risks related to climate change. In fact, the site of Pompeii is located in an area characterized by extreme volcanic hazards posed by Vesuvius and Campi Flegrei (see INGV), high seismicity associated with Apennine faults (see Locati M et al. (2022)), and significant hydrogeological hazards (as can be seen on ISPRA (2018)). Recent relevant events, as reported by FAR-Program (2022) highlight the significance of the impact of climate change. Extreme and/or rapid changes in weather conditions, such as temperature, precipitation, humidity, and wind, directly and indirectly impact the decay of heritage. Rapid changes of temperature, for example, generate phenomena of freeze-thaw cycles, thermoclastism, biological degradation, and corrosion, which historically, have transpired in various ways. As it is reported in Sesana E et al (2021), changes in terms of precipitation could involve the saturation of soils and overloading of gutters and downpipes, with a subsequent higher risk of damp penetration into ancient materials, promoting physical degradation through corrosion, biological activity, and subflorescence due to salt crystallization. Changes in wind, direction and fluctuation, can facilitate the transport of pollutants, salts and sand, which can damage materials and cause erosion. Climate change can also increase the maximum expected intensity or the frequency of natural events leading to flooding, landslides, fire, sea rising, etc. Since these events can affect wide areas, it is necessary to implement large-scale policies that go beyond the single site management. The GPP led to the development of a WebGIS database designed to describe the overall archaeological topography of Pompeii. Each asset is identified by means of an alphanumeric code called a ‘topographical referent’ (figure 1).

Fig. 1. Topographical Referent ID code: description (left) and examples (right) The overall asset is classified by the following ELEMENTs: Vertical Surfaces, Horizontal Surfaces, Isolated Structures and Furnishings. The ELEMENTs are associated to ROOMs of a house, identified by an ENTRANCE NUMBER. The Archaeological Park of Pompeii is subdivided into nine REGIOs, each one subdivided into INSULA blocks. The site contains about 15,000 ROOMs. The public digital archive of the archaeological heritage data of the park is available for consultation online via “ Open Pompeii ” . 3. Monitoring Methodology The proposed monitoring approach aims to comprehensively understand the heritage in order to monitor its condition effectively. The scheme will ensure a rapid assessment of emergency situations, it will establish a list of priorities, and it will facilitate expert and in-depth checks on well-known issues. For this purpose, the model considers multi-scale and multi-level approaches in terms of data and time resolution, and assessment accuracy. It is compatible with the master data and information system already developed in the park and uses WebGIS and IoT tools to develop digital twins to describe the condition of the remains and develop predictive models to support proactive maintenance policies. In particular, the approach consists of three assessment levels: • Local Assessment Level (LA): it is carried out annually to provide an extensive understanding of the condition of the archaeological site, by means of expeditious on-site surveys conducted by expert teams. • General Assessment Level (GA): it is conducted monthly and is carried out by expert operators who use drones and artificial intelligence (AI) tools to provide a sufficient comprehension of the overall condition of the site.