By: W. C. Arthur

The 2018 Tropical Cyclone Hazard Assessment (TCHA18) provides an evaluation of the likelihood and intensity (“how big and how often”) of the occurrence of tropical cyclone winds across the Australian region, covering mainland Australia, islands and adjacent waters. It is a probabilistic evaluation of the expected maximum gust wind speeds with a range of annual exceedance probabilities (or conversely, average recurrence intervals). The assessment is derived using a statistical-parametric model developed by Geoscience Australia called the Tropical Cyclone Risk Model (TCRM). Maximum 0.2-second duration, 10-metre above ground wind speeds are calculated for Standard Australia's AS/NZS 1170.2 (2011) terrain category 2 (0.02 m roughness length) surface conditions, over a 0.02 degree grid across Australia. Maps of average recurrence interval (ARI) wind speeds of 100- and 500-year ARI are provided in a separate product suite.

Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2018.040

By: Jane Sexton, Michael Tait, Heidi Turner, Craig Arthur, David Henderson, Mark Edwards

Ask a Queenslander where tropical cyclones occur and the inevitable response will be, North Queensland. While most of the tropical cyclones have made landfall north of Bundaberg, the cascading and concurrent effects are felt much further afield. The major flooding following Tropical Cyclone Yasi in 2011 and Tropical Cyclone Debbie in 2017 are 2 examples where impacts were felt across the state, and the damage to the banana plantation following Tropical Cyclone Larry (2006) was felt nationally. Acknowledging that climate is influencing the intensity and frequency of intense severe weather hazards, understanding how tropical cyclone hazard varies under future climate conditions is critical to risk-based planning in Queensland. With this climate influence, along with increasing population and more vulnerable building design in South East Queensland (relative to northern Queensland), there is an urgent need to assess the wind risk and set in place plans to reduce the effects of a potential tropical cyclone in South East Queensland.

AJEM 38:4, October 2023, pages 33-39.