University of Canterbury PhD graduate Tom Robinson says his research shows the proposed Haast-Hollyford Highway would be destroyed in an earthquake.
The University of Canterbury scientist previously developed a technique, along with another PhD graduate, to predict the risk of landslides in an earthquake. Dr Robinson has used it to see what would happen on the Alpine Fault that runs through the South Island highway network in a magnitude 8.0 earthquake.
An earthquake of this size has a one-in-three to one-in-four chance of occurring in the next 50 years.
"Just by building this road, we would increase our level of risk for roads to an Alpine Fault earthquake by at least 50 percent, despite the highway only increasing total network length by 3 percent," he says.
"This work shows that, if constructed, the highway would be the worst affected road when the Alpine Fault ruptures, potentially worse even than Arthur's Pass."
UC natural hazards Professor Tim Davies, Dr Robinson's PhD supervisor, says the objective of the research was to test the applicability of the new technique. However, the results can make a difference by aiding infrastructure planners in managing landslide risks, Prof Davies says.
Dr Robinson's research can be used to assess landslides in any earthquake scenario worldwide. He is currently using the technique to assess infrastructure vulnerabilities in South Island roads, rail and power transmission. Further to this, he is using the technique in Nepal to try to understand what the level of risk is to critical infrastructure links.
Dr Robinson says Nepal faced similar challenges to New Zealand but the capacity to deal with the outcomes of an earthquake is "substantially lower".
"I'm hoping to be able to use this technique in Nepal to show how they can streamline pre- and post-earthquake efforts to be as effective and efficient as possible. Identifying which roads are likely to be blocked either prior to or immediately after an earthquake can save considerable time when assessing which regions require emergency assistance," he says.
Dr Robinson's research was recently published in international scientific journal Georisk.