Through a series of analyses in Section 5 and Section 6, we found that research on multi-hazard coupling effects is still in its infancy. Strictly speaking, most studies still fall into the category of domino effects and Na-tech events, only focusing on the triggering relationship between hazards . The existing vulnerability research is not enough to support the risk assessment of multi-hazard coupling scenarios in CPI . The transition from domino accidents and Na-tech events to multi-hazard coupling scenarios is still with a variety of challenges. In the first part of this work, five general forms of multi-hazard coupling effects were identified. Some representative advanced studies have focused on different forms of multi-hazard coupling effects, which are summarized in Table . 8-1. The related multi-hazard scenarios, the involved coupling forms, the advantages and disadvantages associated with these representative studies are provided.