PSI - Issue 78

Mario Graniero et al. / Procedia Structural Integrity 78 (2026) 1040–1047

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structural deformation analysis (Flener et al., 2013). While conventional aircraft-based LiDAR systems have historically been the gold standard for large-area DTM generation, FW-UAVs present a compelling alternative with specific benefits. Conventional airborne LiDAR offers broad coverage and typically higher payload capacities for more sophisticated sensors. However, these operations are generally more expensive, require extensive planning, and have longer deployment times, making them less suitable for rapid response scenarios. In contrast, FW-UAV LiDAR systems, despite potentially having a smaller operational range per flight compared to a full-scale aircraft, excel in their agility, speed of deployment, and cost-effectiveness for localized or targeted missions (Nex and Remondino, 2014; Remondino et al., 2012). They can be launched quickly from a wider variety of locations, making them ideal for assessing specific sections of damaged infrastructure in the immediate aftermath of an event. Furthermore, FW-UAV LiDAR can achieve very high point densities due to their ability to fly at lower altitudes and slower speeds when necessary, resulting in exceptionally detailed DTMs. While conventional aircraft LiDAR can penetrate vegetation to a degree, the lower flight altitude of UAVs can sometimes provide even better ground penetration in densely vegetated areas, leading to more accurate bare-earth models in challenging terrains. While some studies suggest that photogrammetry from low-cost UAVs can yield comparable DTMs under optimal conditions (Jiménez- Jiménez et al., 2021; Kršák et al., 2016), LiDAR maintains a superior advantage in its ability to directly measure distances and penetrate through canopies, providing more reliable ground information regardless of lighting conditions or surface texture (Flener et al., 2013). Therefore, for rapid, high-resolution DTM generation over linear infrastructures in complex or dynamic environments, FW-UAV LiDAR offers a unique balance of efficiency, precision, and operational flexibility that complements, and in many emergency scenarios, surpasses the capabilities of conventional aerial platforms. 4. Conclusions and future developments Fixed-wing Unmanned Aerial Vehicles offer a transformative approach to promoting the safety and resilience of linear infrastructures in the face of natural hazards such as earthquakes and landslides. Their distinct advantages, including rapid deployment, extensive range, high-quality data collection capabilities, enhanced operator safety, and versatile sensor payloads, position them as an indispensable tool for both pre-event vulnerability assessment and post disaster response. The integration of FW-UAV data with advanced data-driven models and artificial intelligence unlocks unprecedented opportunities for accurate seismic and earthquake-induced landslide vulnerability estimation, generation of dynamic 3D interactive maps, and real-time damage detection. These capabilities not only support proactive maintenance and strategic planning but also dramatically improve the efficiency and safety of emergency operations. Specifically, multi-source data fusion, including space-air-ground observations, has proven effective in rapid post seismic disaster assessment. For instance, studies on the 2025 Ms6.8 Xigazê Earthquake in Xizang utilized Differential Synthetic Aperture Radar Interferometry (D-InSAR), high-resolution optical remote sensing, UAV imagery, and airborne LiDAR data to analyze surface deformation and rupture zones, providing a methodological framework for rapid response and secondary disaster mitigation. This integrated approach effectively overcomes the limitations of traditional field investigations and low-resolution remote sensing imagery by providing high-precision, full-coverage post-earthquake surface deformation data (Dou et al., 2025). Furthermore, UAV oblique photography technology significantly enhances geological hazard investigation, detection, and prevention due to its versatility, efficiency, and accuracy compared to traditional methods. This technology aids in creating detailed maps and 3D models from high-resolution, multi-angle images, which are vital for identifying potential geohazards and detecting changes in landforms, vegetation, or waterways for early warning. It is also crucial for quickly assessing impacts on infrastructure and settlements, thereby facilitating efficient resource allocation for rescue and recovery efforts. This contrasts with traditional remote sensing, which often provides incomplete data and less precise modeling due to its inability to capture multi-directional data simultaneously and upload data in real-time for immediate adjustments (Zhao et al., 2024). Despite their immense potential, the widespread adoption of FW-UAV technology for infrastructure monitoring, especially in complex and seismically active geographies like Italy, remains nascent. Future developments should focus on several key areas to maximize their impact. Firstly, there is a need for standardized methodologies for data