Esk Valley after Cyclone Gabrielle. Photo: RNZ/ Nick Monro
A public health researcher is calling for an inquiry into what could have happened during Cyclone Gabrielle under different circumstances, in order to find where the weaknesses lie.
Eleven people died when Cyclone Gabrielle hit the east of the North Island in February.
Professor of public health Nick Wilson says a national inquiry is vital and should imagine how much worse it could have been, for example, if Cyclone Gabrielle had hit Auckland.
"The bizarre thing is that this Cyclone Gabrielle has done potentially up to $15 billion of damage, and there is no national-level review.
"Really, this is such a big event... we need to extract as much information from each event."
A public health briefing from his team at Otago University also raised the prospect of how things could have been worse if the winds and rain had been stronger, or the public response was worse because of distrust in news and government agencies.
It was a matcher for what airlines did after near-misses - "downward counterfactual analysis" that imagines worse scenarios to get lessons from them.
The team found five key ares which may have led to worse outcomes:
- The severity: Cyclone Bola hit with almost twice as much rain - 917mm versus Gabrielle's 540mm - and Giselle with much higher winds - 275kmh versus 146kmh - that contributed to the Wahine's sinking in 1968
- The population in its path: "The cyclone was heading towards the Auckland region but undertook a sharp deviation out to sea"
- The timing: Closer to the earlier Cyclone Hale, or during summer holidays
- The public response: More dis/misinformation could have gone out - "Indeed, some Auckland-based radio hosts played down the danger it posed and complained about a day of school closures"
- The emergency response: Auckland's poor management of the Anniversary Day floods were an example
An inquiry that adopted this approach would uncover "hidden gaps", Wilson said.
"By only looking at what happened, and not what could have happened, we miss weakness in the systems that aim to keep people safe in emergencies."