A simplified methodology for rapid Natech risk assessment of flood-wind-hail multi-hazard scenario

Natural hazard events that trigger technical emergencies (Natech events), as a typical type of multi-hazard, have become a matter of growing concern. In particular, the occurrence of Natech events in industrial areas triggered a number of severe accidents. The present research aims at introducing a sound but simplified methodology to quickly and flexibly assess the Natech risk in a flood-wind-hail multi-hazard scenario. Taking the analysis of atmospheric vertical storage tank as an example, the methodology is shown. This methodology consists of eight steps, relying on the simplified physical models of tank damage caused by multiple natural disasters. In addition, LOC probability and risk are calculated to provide reference for decision makers. The uncertain parameter set (UPS) proposed in the method and the Monte Carlo simulation method can help to purposefully analyze the impact of various parameters in multi-hazard scenarios. New risk assessment of wind-overturning and hail-yielding is implemented. And this method is also applicable to Natech events involving other multi-hazard scenarios and other types of industrial facilities, which helps to quickly evaluate the risk to provide possible reference, and saving time cost and improving the efficiency of decision-making.