The population growth in areas next to sources of natural hazard, the increasing industrialization and complexity of life-lines in metropolitan areas produce an amplification of potential risks associated with natural and man-produced hazard in urban areas.

Consequently, a ranking of environmental risks threatening a territory is a necessary tool for local authorities aiming at addressing public funds to the mitigation of most the highest risks.

Traditional risk analysis considers each risk factor independent from the others. As a consequence of this approach, exposed values are usually defined regardless of interactions among the multiple risks generally impending on a territory.

In this context, multi-risk evaluations are becoming the most efficient instruments for a sustainable territorial planning and for a more competent emergency management, before and during an adverse event. In fact, this methodology allows for a joint analysis and a complete definition of all the risks induced by human and natural sources on a specific area.

Multi-risk approach is a multidisciplinary methodology proper of AMRA which can count on researchers with different expertise in risks’ evaluation fields. A method often used by AMRA for quantitative risks’ estimation is based on Event Tree Analysis, i.e. tree-shaped diagrams, allowing for a description of all the possible events triggered by a risk source and for a probabilities assessment of combined events. Last output of AMRA’s research in this field is related to a joint employment of an Event Tree Analysis with a Bayesian Approach for the evaluation of occurrence probability of adverse events, ensuring, in this way, quantitative and reliability of results.

AMRA is able to define occurrence probabilities of scenarios induced by interactions among different risks’ sources, i.e. cascade effects, through a quantitative approach for the estimation of multi-risk indices considering all adverse events, both single and sequential.

Multi-risk approach joint to GIS methodologies allows AMRA to perform time varying risks’ evaluations supporting territorial planning in the context of environmental risk prevention.