The term Natech refers to natural disasters triggering technological accidents. In fact, because of the interaction between the natural and the industrial risk it is possible that several effects take place in industrial plants and in the storage sites, causing for example damage to pipelines, to process equipment, to storage tanks and consequently the release of hazardous materials.
There are different kinds of natural events or, in general terms, of natural causes of industrial accidents (landslides, hurricanes, high winds, tsunamis, lightning, cold/hot temperature, floods, heavy rains etc.), nevertheless in the present study the attention is focused only on seismic and flood events. In fact, several accidents occurred in the last decades in industrial sites evidenced that typology of natural phenomena may cause severe damages to equipment items, resulting in losses of containment, thus in multiple and extended releases of hazardous substances. Because of these multiple and simultaneous failures with release, cascading events are more likely to occur during a natural disaster than during normal plant operation. Some examples of natech events like the flood in the Samir refinery in Mohammedia, Morocco, in 2002 or the Kocaeli earthquake in Turkey in 1999 are available in the scientific literature or in the accident databases . In both cases the natural event occurred in a refinery and involved several storage equipment items and generated fires and explosions. These reports allow to better understand the particular severity of the industrial accidents triggered by flood and seismic events.
The reference for the prevention of chemical accident in the European Commission is the Seveso Directive II (96/82/EC). The aim of the Seveso Directive is Prevent Major accidents which involve dangerous substances and to limit their consequences for man and environment with a view to ensuring high levels of protection throughout Community in a consistent and effective manner. (Council Directive 1996)
The Seveso Directive is addressed indirectly to Natech risk management; in fact it calls for the analysis of the external events in The identification and accidental risk analysis and prevention methods. The analysis of external events which can lead to chemical accident implies the consideration of the potential threat of natural hazards in the hazard analysis, and carrying out mitigation measures in case an accident occurs.
Nevertheless the methodologies and the actions that can be taken to achieve these requirements are not specified and limited work has been devoted to the development of quantitative assessment procedures for Natech risk.JRC.G.7-Traceability and vulnerability assessmen
