PSI - Issue 78

Carpanese Pietro et al. / Procedia Structural Integrity 78 (2026) 536–543

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3.3. Other hazards With regard to landslide hazard, PERIL uses the classes proposed by ISPRA, which provides national maps also related to landslide hazard (https://www.isprambiente.gov.it/it/attivita/suolo-e-territorio/dissesto-idrogeologico/le frane-1/mosaicatura-della-pericolosita-da-frana-dei-piani-di-assetto-idrogeologico-pai). In particular, ISPRA defines 4 different hazard classes (moderate P1, medium P2, high P3, very high P4), and an additional class where possible landslides have been identified but to which no hazard class has yet been associated (AA attention areas). In PERIL, the latter are assigned a P1 class. On the other hand, weather-related hazards (hail, lightning and wind gust) are derived from historical data provided by Hypermeteo (https://www.hypermeteo.com/), a company that collects and processes meteorological data distributed on digital grids. This data contains information on recorded events for every day of the year between 2013 and 2024 for wind and between 2016 and 2024 for lightning and hail. The data is referenced to a spatial grid with a latitude and longitude interval of 0.1 degrees. To assess the lightning and hail hazard class, the average number of annual events at each grid point is used to divide the Italian territory into four uniformly distributed hazard classes (P1-P4). Similarly, the wind gust hazard class is assigned based on the four quartiles of the mean value of the maximum annual velocity recorded. 4. NatCat model The previous section explained how PERIL assigns hazard classes to buildings, which is useful for preliminary assessments and prioritization lists. The PERIL platform can further investigate two of the natural events, namely earthquake and flood, on which it performs damage and risk analyses in terms of economic losses, safety evaluations, and business interruption estimates. • Conditional analysis: carried out for a specific seismic event that has a certain probability of occurrence (return period), the intensity of which is expressed as PGA (peak ground acceleration) [g]. Specifically, the return periods (TR) for which Peril performs the calculation are the nine options provided in NTC2018 (Italian Ministry of Infrastructures and Transports 2018), namely 30, 50, 72, 101, 140, 201, 475, 975, 2475 years. • Unconditional analysis: consists of the convolution of all possible seismic scenarios that may occur (for all TR) considering their probability of occurrence in an observation time window (1 year, 10 years or 50 years). • Simulated scenario from epicenter and magnitude: is the simulation of an earthquake from the definition of its epicenter (latitude and longitude) and its magnitude. Through attenuation laws (Sabetta and Pugliese 1996), the magnitude is converted to PGA depending on the distance from the epicenter. • Scenario from shakemap: these maps display the intensity of ground shaking produced by past seismic events. In PERIL, INGV (National Institute of Geophysics and Volcanology) shakemaps in PGA of the main shocks of the seismic events of the last decades are uploaded (L’Aquila 2009, Emilia 2012, Garfagnana -Lunigiana 2013, Italia Centrale 2016-2017, Mugello 2019) (http://shakemap.rm.ingv.it/shake/archive/). Once the seismic input (PGA) is defined selecting one of the analyses described above, the user needs to choose the vulnerability model to be used for each building type to be analyzed, considering use and characteristics derived through the input enrichment module (§2). In PERIL, vulnerability is defined through fragility curves, which represent the probability of reaching or exceeding a damage state. Currently, the pre-loaded curves selected by default are those developed by Donà et al. (2021) for residential masonry buildings, Rosti et al. (2021) for residential reinforced concrete buildings, and FEMA's Hazus curves (FEMA 2022b) for industrial buildings, but other customized models can be entered by the user. To carry out risk analyses and to calculate economic losses, each damage state is associated with a monetary loss estimated as a percentage of the building reconstruction cost. The total economic loss is then computed as the sum 4.1. Seismic risk analysis PERIL performs four types of seismic analysis.