Multihazard Risk Assessment and Cascading Failures

A variety of natural extreme events, including earthquakes, landslides, volcanic eruptions, tsunamis, river floods, winter storms, wildfires and coastal phenomena, threaten different regions of Europe. This leads to populations suffering losses not only from individual hazards, but also from multiple events that occur in combination.

In both their occurrence and their consequences, different hazards are often causally related. Classes of interaction include triggered events, cascade effects and the rapid increase in vulnerability during successive hazards. Effective and efficient risk reduction, therefore, often needs to rest on a location-based synoptic view.

Planners and policy-makers, and the scientists who inform their judgements, usually treat the hazards and risks related to such events separately from each other, neglecting interdependencies between the different types of phenomena, as well as the importance of risk comparability. Resolving this deficit will improve their ability to take risk reduction measures in a cost-effective way and in doing so, strengthen societies' resilience to natural disasters.

Our group is currently involved in “Risk Analysis of Infrastructure Networks in response to extreme weather” (RAIN) project (2014–2016). It is aiming to provide an operational analysis framework that identifies critical infrastructure components impacted by extreme weather events and minimise the impact of these events on the EU infrastructure network. The project has a core focus on land based infrastructure with a much wider consideration of the ancillary infrastructure network in order to identify cascading and inter-related infrastructure issues.

The project includes a “hazard identification” work package. Our group is analysing return periods and extents of river floods and coastal floods in EU countries under present and future climate. The investigation will also include flood defences and provide output for the risk analysis framework that is developed in the work package lead by TBM faculty of TU Delft. The GIS dataset of flood hazard will be complimentary to dataset created by other partners (precipitation, storms, forest fires, winter weather events and others).

Our group was previously involved in:

• “New Multi-Hazard and Multi-Risk Assessment Methods for Europe” (MATRIX) project (2010–2013). Our investigations included cascade effects in a multi-hazard approach and multi-type risk assessments.
• “Resilient and Sustainable Infrastructure Networks” (RESIN) project at UC Berkeley (2009–2011). In this project we have contributed to studying risks for interconnected infrastructures (levees, gas, power) in the Sacramento – San Joaquin delta in California.