PSI - Issue 84

Luciano Pavesi et al. / Procedia Structural Integrity 84 (2026) 583–590

584

review under responsibility of the scientific committee of the Conference Keywords: Flood risk, Infrastructures, Bridges, Hydrologic-hydraulic Modeling, Satellite Data Through this approach, it becomes possible to assess peak discharges and corresponding water levels at the location of every bridge or crossing structure in a coherent, scalable, and physically-based manner, replacing empirical and locally inconsistent estimations. This work presents early results demonstrating the feasibility and added value of RESCUE_SAT in bridging critical data gaps, supporting more accurate infrastructure assessment in relation to flood risk, and offering a scalable solution for flood risk assessment in the context of climate adaptation and infrastructure safety. © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference 1. Introduction Floods are one of the most significant natural hazards on a global scale: it is estimated that between 1.81 and 2.3 billion people are currently exposed to flood events with a return period of 100 years (Rentschler et al., 2022; Moody’s, 2023). This value is projected to increase in next decades due to population growth in flood-prone areas and climate change (Jongman et al., 2012; Winsemius et al., 2016; Rogers et al., 2025). Although there is still no uniform climate signal emerging in Europe in historical river flow series (Blöschl et al., 2019), numerous studies highlight significant regional trends and agree that the intensification of the hydrological cycle already underway (Madakumbura et al., 2019; Markonis et al., 2019) will lead to an increase in extreme precipitation and the likelihood of flooding events across most of the continents (Alfieri et al., 2015; Dottori et al., 2023; Ingram, 2016; Seneviratne, 2021). Furthermore, in complex societies, where social, economic and infrastructural systems are interconnected, floods can trigger cascading effects when critical link infrastructures (such as bridges) or defense structures (such as levees and dams) fail (D’Angelo et al., 2020; Marco, 2012). This has consequences that amplify the impact of floods and increase systemic risk across affected territories. Within this framework, bridges are particularly sensitive elements, as they act as key nodes in road networks and control access to facilities and primary services. Their disruption during flood events can therefore isolate communities, assets and interrupt healthcare system practices (Wassmer et al. 2025); in addition to exposing the structures themselves to direct flood-related processes such as overtopping, foundation scour, hydraulic loading and debris accumulation, often compounded by pre-existing vulnerabilities related to age, deterioration and non-systematic maintenance. In Italy, the growing awareness of these issues has led to the development of specific regulatory instruments for infrastructure risk management. The Guidelines issued by the National Agency for the Safety of Railways and Road and Motorway Infrastructures (ANSFISA) for risk classification, safety assessment and monitoring of existing bridges introduce a multi-level framework aimed at ensuring a systematic, standardized and risk-informed management of the national infrastructures. This framework is structured as a progressive sequence of assessment levels, ranging from inventory censuses and basic data collection to visual inspections, preliminary condition assessments, advanced structural verifications, specialized analyses, and continuous monitoring systems. The depth of analysis is calibrated according to the criticality of each structure. A key part of the ANSFISA Guidelines is the use of a multi-hazard assessment, which looks at how structures are affected by different natural and non-natural hazards. These include flooding and related scour processes, seismic events, geotechnical and hydrogeological hazards, as well as operational traffic conditions and ageing. Regarding flood hazards, the ANSFISA Guidelines introduce a standardized methodology designed to support preliminary assessments homogeneous hydrological modeling framework that enables a physically-based, automated estimation of design peak discharges across Italy, including secondary river networks typically not mapped. This methodology leverages the RESCUE model (laRgE SCale inUndation model, Pavesi et al., 2022), which combines regionalized rainfall and infiltration data to estimate critical flow rates along the entire hydrographic network. In addition to discharge, the model also provides estimates of water surface elevations along the river network, which are essential for the hydraulic verification of bridges and other crossing structures.