National Volcano Model: Probabalistic volcanic ash building damage

This research develops the first nationally consistent, probabilistic assessment of the damage volcanic ash could cause to buildings across Aotearoa New Zealand. The National Volcano Model brings the following together:

• The likelihood and size of future eruptions
• Modelling of where volcanic ash may fall
• Information on New Zealand’s building stock.
• New locally developed models of how different building types and components respond to ash loading.

This allows researchers to estimate potential building damage and repair costs and to compare volcanic ash risk consistently across regions and volcanic sources.

The results show that volcanic ash risk varies considerably across the country, and reflects:

• the differences in volcanic hazard
• the location and value of buildings
• buildings' vulnerability to ash.

Bay of Plenty, Waikato and Hawke’s Bay make the largest contributions to estimated average annual building loss, while rare eruptions can also generate substantial losses in regions with lower annualised risk.

The model provides a foundation for better-informed emergency management, resilience planning and investment decisions, and can be expanded over time to include other volcanic hazards and types of assets.