Mount Pinatubo – a case study of a multihazard network

The Philippines location on the edge of the Pacific makes it a nexus for tectonic and climatic hazards and a real-world example of the possible complexities surrounding multi-hazard assessment, risk management and governance. This inherently multi-hazardous environment and the well documented events over the last few decades provide an opportunity to characterise multi-hazards over temporal and spatial scales beyond those previously considered. We aim to switch from linear considerations of multi-hazard cascades and coincident events to a deeper understanding of more systemic multi-hazard interrelationships (networks). We will review the effects of these spatially and temporarily diverse events on multi-hazard governance and the complexity of managing events that cross institutional and administrative institutions. In this case study we will present the initial mapping of physical and social multihazards associated with Mount Pinatubo from 1990 to the present day. The famous explosive eruption of Mount Pinatubo on the 15th of June 1991 is often referenced as a multihazard event due to the coincident arrival of Typhoon Yunya with the main paroxysmal phase of the eruption. In reality however, this eruption was part of a larger complex network of independent, triggering, compound and change condition hazards that extend over a timeframe of decades. By fully mapping these interactions we hope to stress the lessons that can be learnt from this event and highlight the complexities in managing hazards that cross disciplines and authorities.