Terrorist actions often strike building and civil critical infrastructures of strategic interest, such as government buildings, airports, harbors, bridges, head offices of large corporations. The same buildings and critical infrastructure are often among the facilities damaged in a natural disaster. During such events the above facilities may exceed their functional or structural limits and this can be visible. On the other hand, they can also suffer enormous damage to their capacity without producing any apparent visible signs. Such damage, for instance, in the case of an earthquake, can render the facility incapable of surviving consecutive aftershocks. These aftershocks take place within few hours or days of the earthquake and can have an intensity of up to 90% of the earthquake intensity.
The post-crisis damage assessment process for constructed facilities is based mainly on on-site inspection by experienced engineers. When the visible signs of damage are not of the kind that points to a definitive damage or non damage state, further analysis is necessary. The problem is compounded by the shortage of experienced inspectors and the inevitable time delay caused by an in-depth structural analysis during which time a conservative position has to be taken and the facility stays closed. This is extremely painful in the case of critical facilities, such as, for instance, buildings necessary for the planning and management of early and full recovery (e.g., the Ministry of the Interior, or civil protection agencies), or hospitals, police and fire stations, bridges and tunnels essential for the passage of emergency vehicles.
RECONASS will provide a monitoring system for constructed facilities that will provide a near real time, reliable, and continuously updated assessment of the structural condition of the monitored facilities after a disaster, with enough detail to be useful for early and full recovery planning. The above assessment will be seamlessly integrated with automated, near real-time and continuously updated assessment of physical damage, loss of functionality, direct economic loss and needs of the monitored facilities and will provide the required input for the prioritization of their repair.
Advances in Information and Communication Technologies
In case of large scale events (e.g., an earthquake or regional conflict), recent advances in Information and Communication Technologies, including Earth Observation, can shorten the time for an initial inspection to identify damaged constructed facilities. For instance, following the 2010 Haiti earthquake, vertical aerial imagery of 0.15 m resolution allowed damage delineation that was an order of magnitude more accurate than that generated based on 0.5 m satellite imagery. Still, this is information that is based exclusively on what can be seen from outside the facility and can replace a first, rapid inspection, to quickly screen out the obviously safe and the obviously unsafe facilities, that usually takes some days. Following the Haiti earthquake also the utility of multi-view oblique aerial imagery from the Pictometry system to detect and quantify structural damage of buildings was assessed. This work has shown that physical damage to roofs and facades can be identified (visual signs of damage, as well as damage revealed by geometric deformation such as tilting). Systems such as Pictometry, but in principle any airborne imaging system that permits controlled oblique image acquisition, allow a building to be imaged from all four sides (barring occlusion by vegetation or closely-spaced buildings) and from above. While this potentially allows a comprehensive appraisal of the state of a buildings, it cannot replace the detailed inspection that follows to provide a more reliable estimate of the structural condition of the facility that takes some weeks.
In RECONASS the detailed assessment of damage in the monitored facilities will be used for the speedy local calibration of satellite and oblique aerial photography dramatically reducing the required time to inform the post disaster/crisis needs assessment process and provide base data for reconstruction efforts.
The above will be part of the RECONASS next generation post-crisis needs assessment tool in regards to construction damage and related needs. This tool will enable fusion of external information, allow for future expansion of the system, provide international interoperability between the involved units for reconstruction and recovery planning and support the collaborative work between these actors.
