National Geographic talks with Jeff Keppert, head of High Impact Weather research at the Bureau of Meteorology about the likelihood of cyclones hitting Australia and how we, as a nation can prepare for such an event.
The recent events in the gulf and across the pacific have caused mass devastation, how likely is it that events like this will happen in Australia?
Australia can, and has, seen cyclones of broadly similar wind speed intensity to Irma, and that have produced major flooding like Hurricane Harvey. However, major disasters occur when a severe event impacts a vulnerable population. Australia’s coastal areas are relatively sparsely populated, especially in WA and the NT, so it is less likely that a large population would be impacted. However, a major cyclone impact on one of our larger population centres in the tropics would have a substantial impact.
Storm surge and riverine flooding are deadlier hazards than wind, so it is very important that people in vulnerable areas listen to the authorities and evacuate when they are advised to do so.
We have quite stringent building standards, and a good level of conformity to them, so most structures will only experience light to moderate wind damage, and even a partially damaged structure can still provide good shelter from the wind for its occupants.
Like the US and Caribbean, we have a highly effective warning system, so populations are well prepared for an event, which demonstrably saves lives and property.
What kind of damage would Australia be looking at if we did have similar weather?
Flooding, both riverine and storm surge, would be likely. Many houses would be partially damaged, some with roofs removed. However, the total destruction which we saw in Tropical Cyclone Tracy in 1974 would not recur, because building standards, and our forecast and warning services, have improved enormously since then. In Tropical Cyclone Tracy, communities received forecasts of only the next 12 hours of movement, whereas now they can expect a few days warning of a possible impact. Those better forecasts, which rely on advances in scientific knowledge, and new technologies such as supercomputers and satellites, enable better preparation and save many lives.
When the next severe cyclone impacts Australia, we can expect that trees and powerlines would be down, and there would be periods when communities were without power and water. We might see a small number of fatalities, more likely from drowning in flood waters than wind impacts. Such deaths may be avoidable, for example if people avoid attempting to cross flooded rivers.
What precautions can we take as a country?
We already do much of what is necessary – we have an excellent meteorological service to warn of the onset of an event, well prepared emergency services, and strong built infrastructure. However, the growing coastal population, climate change, and increased societal expectations means that we need to continue to improve our services. Sea level rise due to climate change has already increased the risk of flooding due to storm surge. We also expect to see heavier rain in cyclones, and that the most intense storms will gradually become more common. For all of these reasons, we need to continue to improve our tropical cyclone forecasting and warning services, maintain a high standard of built infrastructure, and avoid development in especially vulnerable areas such as the coastal fringe and flood plains.
Regardless of when or if a cyclone does hit, Australia will be prepared.
Lead image: A composite image from a NASA satellite shows cyclones Lam (left) and Marcia (right) as they make landfall in Australia, 2015. PHOTOGRAPH BY NASA EARTH OBSERVATORY