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Departments/Research
By Neil Jamieson, Research Leader – Wind Engineering, Opus International Consultants
Wind damage and resilience
As New Zealand has just experienced its worst year on record for weather-related losses, an engineering consortium is investigating ways to improve our resilience to severe windstorms.
NEW ZEALAND’S vulnerability to extreme weather is widely recog- nised, with population centres and infrastructure assets often located in coastal or hilly areas and frequently exposed to strong winds.
High cost from extreme weather events
In many areas, wind loading dominates structural design, and we are currently ranked as a high hazard for many ooding and storm events by the Global Facility for Disaster Reduction and Recovery. Extreme weather events have caused signi cant damage, disruption and social and nancial cost.
In December 2017, a media advisory from the New Zealand Insurance Council (NZIC) revealed that 2017 was the worst year on record for weather-related losses. The NZIC website shows that, from 2013 to 2017, insured weather-related losses have cost almost $800 million. This does not account for uninsured losses, damage to lifeline services such as water, sewerage, power, telecommunications, disruption, delay or loss of production costs.
Consortium looking to improve resistance to windstorms
The New Zealand Wind Engineering Consortium is undertaking a 4-year project to improve New Zealand’s long-term resilience to severe windstorms and reduce their impacts and costs on people and infrastructure. The consortium comprises Opus Research, NIWA and the University of Auckland.
The project’s four main objectives are to:
● compare wind damage records and full-scale wind speed data with
wind speed predictions from a sophisticated computer model
Figure 1: Canterbury windstorm NZCSM simulation capture. Yellow to red regions signify higher wind speeds.
● evaluateexistingandhistoricalfull-scalewinddata
● engage with the insurance industry and lifeline organisations to
promote appropriate and accurate recording of damage data
● assess the potential e ects of climate change on extreme wind speeds.
First steps – comparing past events and model
Step 1 has involved comparing wind damage records with full-scale wind speed data and wind speed predictions from a sophisticated high-resolution weather simulation model called the New Zealand Convective Scale Model (NZCSM).
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IMAGE COURTESY OF NIWA