The national Tropical Cyclone Hazard Assessment (TCHA) defines the severe wind hazard posed to Australia based on the frequency and intensity of tropical cyclones making landfall around the Australian coastline. Contact us at hazards@ga.gov.au if you need further information. URL: https://www.ga.gov.au/about/projects/safety/tcha <b>Value: </b>The TCHA provides vital information to emergency managers, town planners and infrastructure owners to plan and reduce the threat of tropical cyclone hazard on the Australian coast, and for the insurance industry to understand the tropical cyclone risk as an input to pricing insurance premiums. The TCHA is a key data source to calculate local cyclone impact models for the development of evidence-based disaster management plans, evacuation plans or inform infrastructure planning or mitigation strategies. High risk areas can be identified and prioritised for further analysis, or to extract scenarios to explore risk mitigation and community safety at a local and regional level. The TCHA includes a catalogue of synthetic tropical cyclone events (including tracks and wind fields), hazard profiles for selected locations across Australia, and maps of annual recurrence interval (ARI) wind speeds due to tropical cyclones. Geoscience Australia provides essential evidence based information to government and emergency managers around Australia to improve our communities' ability to prepare for, mitigate against and respond to natural disasters. <b>Scope: </b>Continental scale.

Queensland Fire and Emergency Services are leading the development of consistent risk information relating to the potential impacts of disasters across Queensland. The stated aim is to ensure all local, district and state government stakeholders have access to the same information to guide risk-based planning in the preparation for natural disasters. This extends to future projections natural hazard activity, including tropical cyclones (TC), in the Queensland region. To achieve this last objective, Queensland’s Department of Environment and Science (DES) have undertaken a program of regional climate simulations, with a view to informing long-term planning decisions. When it comes to TCs – a major cause of disasters in Queensland – many of the stakeholders want to answer the question: “How many severe tropical cyclones will the future hold for us?”, or similar questions around the likelihood of TC occurrence. To answer this, DES and Geoscience Australia are interrogating the regional climate simulations to extract Tropical Cyclone-Like Vortices (TCLVs). The behaviour of these TCLVs is then analysed to understand changes in frequency, intensity and spatial distribution. The TCLVs – with some additional bias corrections - can also be used as input to stochastic models that can provide probabilistic wind hazard information across the entire state of Queensland. In this paper we demonstrate the challenges of extracting TCLVs from regional climate models and the bias corrections required to make useful projections of TC activity into the future. Abstract presented at the 2020 Australian Meteorological and Oceanographic Society 2020 National Conference (http://amos-2020.w.amos.currinda.com/)

Severe TC Vance was one of the most intense cyclones to impact mainland Australia. The observed damage to buildings could be explained in terms of structural performance of those buildings. Combining the structural vulnerability of housing with an estimate of the maximum wind gusts, we can explore the possible impacts that a repeat of Vance would cause in Exmouth, and compare the outcomes with what occurred in 1999. The analysis of the impacts of TC Vance on present-day Exmouth shows that very few houses would be completely destroyed. Not surprisingly, older houses (pre-1980’s construction era, excluding the US Navy block houses) would dominate those destroyed, and most likely the timber-framed style houses, many of which were substantially damaged in TC Vance.

An evaluation of the likelihood of tropical cyclone-related extreme winds, incorporating local effects on wind speed.

Severe TC Vance was one of the most intense cyclones to impact mainland Australia. The observed damage to buildings could be explained in terms of structural performance of those buildings. Combining the structural vulnerability of housing with an estimate of the maximum wind gusts, we can explore the possible impacts that a repeat of Vance would cause in Exmouth, and compare the outcomes with what occurred in 1999. The analysis of the impacts of TC Vance on present-day Exmouth shows that very few houses would be completely destroyed. Not surprisingly, older houses (pre-1980’s construction era, excluding the US Navy block houses) would dominate those destroyed, and most likely the timber-framed style houses, many of which were substantially damaged in TC Vance. Published in the Australian Journal of Emergency Management July 2019 edition

<div>The region of coastal South East Queensland (SEQ) is a large concentration of population, industry, and infrastructure important to the economy of Queensland and of Australia. The region is also subject to severe storms that generate damaging winds, particularly as result of thunderstorm and tropical cyclone activity. Older residential housing has historically been the most damaged in such storms, contributing disproportionately to community risk. This risk posed by severe wind is not well understood, nor are the optimal strategies for managing, and potentially reducing, this risk. In this hazard context, this project was initiated based on a joint proposal developed by Queensland Fire and Emergency Services (QFES), Geoscience Australia and the six coastal local governments in SEQ in January 2020. The objective was to gain an improved understanding of the wind risks in this region and to develop actionable information that could inform future strategies to manage and reduce risk in these areas, with broader application to other local government areas. The project proved to be of great interest to a broader range of stakeholders, including the insurance industry, some of whom became formal partners, while others participated as observers. </div><div><br></div><div>The management of wind risk requires a sound evidence base for decision makers. While the information developed in this project has significant uncertainties, the outcomes are considered a representative view of wind risk in a coastal region that is home to nearly 60% of the Queensland population. The work has developed an improved understanding of the three primary risk elements of wind hazard, residential exposure and vulnerability. This has been achieved through a broad collaboration that has entailed the sharing of data, domain expertise and consensus building. This, in turn, has been translated into an assessment of scenario impacts, local scale risk, and the nuancing effects of resilience on the outcomes. An exploration was carried out of the effectiveness of a range of retrofit strategies directed at addressing the residential buildings in our communities that contribute the most wind risk in South East Queensland. The outcome are expected to be a valuable resource for all the project partners and stakeholders in the areas of planning, preparation, response, recovery and strategic mitigation.</div>

As part of the 2018 Tropical Cyclone Hazard Assessment (TCHA), we compiled the geospatial raster dataset that can be accessible to internal and external users via ArcGIS online and can be integrated for building additional geoprocessing applications. This web service gives more stable and easy access to data and interactive maps. With having separate geospatial layers for each recurrence interval- i.e. 5 through 10000 years, users can toggle between the layers and evaluate the changes in wind speed (km/hr) and potential areas at risk on the fly.