Theoretical model for cascading effects analyses

In case of exceptional events of natural or anthropogenic type, the elements at risk (people, buildings, infrastructures, economy, etc.) are often hit by sequences of ‘cascading events’, function of time and space, caused by the triggering event (earthquake, landslide, volcanic eruption, fire, electric failure, etc.). Generally, sequences of events can involve the same element at risk, and the combined effects of cascading phenomena can strongly amplify the impact caused by single events in terms of extension of the affected area and damage level. The final impact on the territory can be significant and require to be carefully assessed in terms of emergency planning and management. This paper discusses from a theoretical point of view the modelling needs and the main issues to be taken into account in the development of simulation tools aiming to include cascading effects analyses to effectively support decision-makers in their preparedness and disaster mitigation strategies in the framework of emergency planning at local, national and international level. The model aims at developing cascading effects scenarios at different level of detail, depending on the availability of inventory/exposure data for the different categories of elements at risk and hazard/impact models for the various hazard sources. It has been developed within EU-FP7 SNOWBALL project (Lower the impact of aggravating factors in crisis situations thanks to adaptive foresight and decision-support tools, 2015–2017).