One of the main problems of emergency management in case of damage reported by historic buildings after an earthquake is represented by immediate damage assessment. In fact, nowadays it is not possible to use techniques other than the personal evaluation carried out by first responders.
Being aware of the situation is one of the most important goals that emergency services need when they design the systems and the procedures to be used during or in the aftermath of a disaster. Situation awareness has many different aspects and needs a flow of information (possibly) in real time from a wide variety of data sources. Such data feed the systems that let emergency managers to assess the situation and take their decisions.
In this framework, the research and the end-user’s needs in the field of Cultural Heritage protection are aiming to integrated systems, featuring sensors and state-of-the-art platforms that have to be built in order to offer the needed information about the conditions of artefacts and the damages they’ve suffered for any kind of natural or man-made reason. According such strategy, heterogeneous and distributed data sources should communicate among the main system, generating a flow of data and information through the traditional internet channel. In this framework, sensors infrastructure based on UAV for surveying, diagnosis and monitoring open-space Cultural Heritage sites could be part of a system that would need technologies and innovative approaches to recognise images (collected by UAVs) along with models and techniques of information fusion.
Exploiting complex event processing techniques and technologies, the extracted information and/or the deducted/determined domain events, would be aggregated and correlated each other in order to bring out potential dangerous or critical situations, ranging from the recognition, validation and localization of signals and events that may suggest the need for monitoring, surveying or warning for disaster prevention, assessing the level of risk (Surveillance & Monitoring Services, Surveying & Diagnosis Services, Quick Damage Assessment Services).
A case study: the 2016 earthquake in Central Italy
In the 2016 earthquake in central Italy an increasing use of drones operated by Italian firefighters (CNVVF) has been recorded, from the early stages of the emergency, in order to have a quick and detailed overview of the magnitude of the damage suffered by major historical and artistic buildings. Such activity has been carried out in the framework of the new procedures adopted to secure buildings damaged in large scale emergency.
The same tools were used to define the urban areas with the highest number of building collapses. The drones, equipped with instrumentation for the photographic survey, have allowed the acquisition of a quantity of gigabytes of high-resolution images of the state of post seismic event locations. In particular, the flight of drones helped to identify the state of damage of all the historic buildings and churches of great artistic importance, located in the red area or not allowed area. These data analysis was significant in order to assess the real risk of further collapses and to design effective shoring systems to support unsafe parts still standing.
The aerial photogrammetric data obtained with several daily sorties of drones, are served by specific input software for rapid return and creation of 3D models, or integrated with cadastral data and geomorphological were a valuable support for the knowledge of the actual operating environment where the teams of firefighters intervened for the search and rescue people. In addition, this post processing has enabled, at the end of the rescue of the population, even a more accurate assessment of the damage and consequently a cost estimate as early as the early stages of the emergency.
Obviously, the accuracy of the data obtained (eg. point clouds, surface models and orthophotos) is not comparable with other system such as LIDAR, however, it represents a valid activity rescue tool support allowing to achieve a good evaluation of the severity of the scenario, and then an estimate of the timing necessary for the refurbishment of the primary infrastructure such as roads, electrical networks etc..
In the specific context, the Italian Fire Corps (CNVVF) special units experts in topography during rescue operations (and able to initiate the procedures for mapping), have scoured the areas affected by the quake. The VHF radio network of the CNVVF (equipped with GPS module and interfaced to specific software on tablet for tracking and geo-referencing), has let them to prepare maps where the information gathered from multiple sources, were processed by experts in GIS systems and transformed it in shapefiles or other formats widely used on platforms such as Google Maps. In this kind of scenarios, the activities needed to assess and restore safety of historic or cultural buildings can be supported by the research as the one carried out in the H2020 STORM project. The task of assessing quickly and in safety condition the damages suffered by historical or cultural buildings has brought to a wide use of UAVs by the CNVVF in the 2016 earthquake. The images recorded by the sensors that have equipped UAVs have been useful to emergency tasks, but their utility would be boosted by the comparison between data detected by LIDAR before and after the disaster event. The STORM pilots scenarios are aiming at integrating UAVs, LIDAR images and procedures shared between cultural heritage managers and CNVVF, in order to let them assess on the scenario and with the best possible resolution the damages a natural event has caused to buildings.
A paper concerning the use of drones (STORM project and the use of UAV to improve emergency management of disasters threatening cultural heritage), presented in the UAV&SAR2017 (Rome, 29th March, 2017) Workshop can be downloaded here: Guerrieri Marsella STORM_UAVSAR_def (1)