Domino and cascading effects in complex events and territorial contexts

In the paper, a discussion about domino and cascading effects due to triggering hazards is presented. The importance of considering secondary or concurrent events and the complexity of the affected territorial systems, is actually a key topic in scenario and risk studies. This kind of approach actually increases the difficulties in obtaining detailed results, but permits to have a more complete view on the effects of dangerous events, not only in the directly affected areas, but also in wide and sometimes unexpected, times and spaces. A framework representing the logic sequence of the effects (direct, secondary, etc.) due to different hazards (single or cascading, or concurrent), considering the characteristics of the affected territory, in terms of systemic vulnerabilities, response capacity and interdependencies among of the involved sectors, to obtain a scenario of high order, is proposed. The framework is applied to two real cases occurred during central Italy seismic swarm 2016-2017: the landslides triggered by earthquakes on the road system and, the snowstorm and the power outages in January 2017.