Making the Big Calls During Public Emergencies

Should they stay or should they go now?

September 2018 and the Northern hemisphere’s storm season has started with multiple storms affecting many countries. And it’s still early days.

Hurricane Florence has battered North and South Carolina leaving At least half a million homes without power and warnings for flash flooding extend to the surrounding states. The storm has been the cause of eleven people losing their lives.

Meanwhile, across Asia more than three million people have been moved to safety in the Philippines and southern China as Typhoon Mangkhut moved across the region wreaking havoc along the way.

The decision to evacuate towns and cities in southern China came as Hong Kong was left reeling by savage winds of up to 173 kilometres per hour and gusts of up to 223 kmh. Worst hit by far has been the Philippines, where at least fifty-four people have been reported killed when the, then super-typhoon, known locally as Ompong hit northern Luzon.

The Philippines evacuated thousands of people, deploying soldiers and positioning emergency provisions as the Typhoon threatened more than four million people in the north of the country. With windspeed measured at 285 kmh it was classified as a category 5 storm.

Whilst in all these cases, the mass movement of people has proven effective, it hasn’t always been a straight forward affair. After all, evacuating prior to a major event such as this seems common sense and making that call to alert and advise the public on the face of it, seems rather straight forward.

And yet it hasn’t always been that simple. In 2017 Hurricane Harvey churned toward the Texas coast as public officials issued conflicting advice to the public. Houston Mayor Sylvester Turner told people to stay put. “Don't evacuate.” he said. Meanwhile Texas Governor, Greg Abbott conversely told Houston residents that if he were living in the area, he'd head north - evacuate and go someplace else for a little while.

Throughout all of this successive Hurricanes were lined up in the Caribbean. Staring down an imminent Hurricane backed up by other storms appears to make the decision to evacuate a no-brainer. Yet many officials defied what appeared to be common sense and continued to advocate for residents to stay. So, what was going on here?

Lessons learned in 2005, just a few weeks after Hurricane Katrina devastated New Orleans, Hurricane Rita made its way toward Houston. Rita was even stronger than Katrina — and Houston had just witnessed what happened to New Orleans residents who decided to wait out the storm. Nobody wanted to repeat that mistake.

The result: The largest evacuation in U.S. history. Texas legislators estimated that 3.7 million people left the Houston region in the evacuation effort. Unfortunately, dozens of people died on the road — in a horrific bus fire, in traffic accidents, of heat stroke in 38C degree heat. Cars ran out of petrol leaving abandoned vehicles to amplify the traffic chaos.

After all that, Rita changed course and missed Houston. The direct death toll from the storm itself was fewer than 10, a fraction of the death toll of the evacuation.

In all large-scale emergencies, the calculations for public warnings are immense. This past week the hurricanes battering the Caribbean successively means that few islands in the archipelago have anywhere to evacuate to, so a less complex decision to advise residents to take shelter was broadcast.

Mount Agung 2018 - Bali, Indonesia

Mount Agung 2018 - Bali, Indonesia

We in Australia are staring down an extreme fire danger season due to a dry winter. This may result in the requirement for evacuations of country areas or even city fringes. Bali and Vanuatu during 2018 have had to evacuate residents due to volcanic eruptions which has impacted the lives and livelihoods of tens of thousands of people.

Whilst weather prediction is incredibly accurate nowadays and organisations such as Australia’s CSIRO have developed incredible mapping technologies that can predict fire spread and smoke plume directions, for situations such as bushfires, making the call for evacuations on a large scale is still a mix of science, experience, skill and luck.