The National Hazard Impact Risk Service for Tropical Cyclone Event Impact provides information on the potential impact to residential separate houses due to severe winds. The information is derived from Bureau of Meteorology tropical cyclone forecast tracks, in combination with building location and attributes from the National Exposure Information System and vulnerability models to define the level of impact. Impact data is aggregated to Statistical Area Level 1, categorised into five qualitative levels of impact.

People, homes, businesses and infrastructure have been severely impacted by the recent flooding in Tweed Shire. Information is needed on the nature of these impacts to assess losses, assess community recovery and contribute to the development of strategies to reduce risk in the future. To collect this information a survey team has been established to gather data on the impact on buildings and businesses. The survey team is being led by Geoscience Australia, the national agency for geoscience research and spatial information, in collaboration with RMIT University and the Tweed Shire Council.

Wind multipliers are factors that transform wind speeds over open, flat terrain (regional wind speeds) to local wind speeds that consider the effects of direction, terrain (surface roughness), shielding (buildings and structures) and topography (hills and ridges). During the assessment of local wind hazards (spatial significance in the order 10's of metres), wind multipliers allow for regional wind speeds (order 10 to 100's of kilometres) to be factored to provide local wind speeds. <b>Value: </b>The wind multiplier data is used in modelling the impacts (i.e. physical damage) of wind-related events such as tropical cyclones (an input for Tropical Cyclone Risk assessment), thunderstorms and other windstorms. <b>Scope: </b>Includes terrain, shielding and topographic multipliers for national coverage. Each multiplier further contains 8 directions.

A presentation delivered at the Australia Reinsurance Pool Corporation / Organisation for Economic Co-operation and Development (ARPC/OECD) Terrorism Risk Insurance Conference held in Canberra from 6-7 October 2016. The presentation focusses on GA's work with the ARPC in developing a capability to estimate insured losses due to blast in Australian cities.

Australian Community Climate and Earth-System (ACCESS) Numerical Weather Prediction (NWP) data is made available by the Bureau of Meteorology for registered subscribers such as GA. ACCESS-C3 (City) model is a forecast-only model performed every 6 hours and consists of grid coordinates covering domains around Sydney, Victoria and Tasmania, Brisbane, Perth, Adelaide and Darwin. ACCESS Impact Modelling (ACCESS-IM) System utilise information from ACCESS-NWP on the forecast wind gust speeds ground surface (single-level) at 10 metres, simulated by the ACCESS-C3 model, for the time period of 0-12, 12-24, 24-36, 0-36.

Limited data from emergency services for the April 2015 East Coast Low (ECL) event initially investigated. SES call-out data provides spatial coverage, but does not capture detail of the damage to buildings. EICU data has detailed information, including indicative damage state, but limited spatial coverage. Neither dataset consistently links the damage to the hazard that caused it. Showing that the impact forecasting process adds value beyond the underlying hazard forecasts in this situation is challenging. EICU data can help to calibrate the vulnerability functions applied to model-based hazard forecast data. The SES callout data can help evaluate whether the indicative damage rates for an area are reasonable, through use of a service demand metric. Service demand is the number of callouts compared to the number of buildings for a statistical area (e.g. mesh block, SA1 or local government area). We use the total building count in each area, as the SES callout data does not differentiate between residential and non-residential buildings. It also includes callouts for downed trees or power lines that may not have directly caused structural damage to buildings. Service demand is compared to mesh block-based impact forecast data for the 2015 ECL, using existing heuristic vulnerability functions for severe wind. We recognise these functions are not calibrated against forecast model data, but provide a starting point from which we can establish the workflow while working towards refined vulnerability functions in parallel. The project has sourced EICU and SES post-event survey data, and high-resolution model (reanalysis) data for two additional severe wind and rain events to improve the calibration of the vulnerability functions. Poster presentation at the 2019 AFAC Conference

<div>The Severe Wind Hazard Assessment for South East Queensland (SWHA-SEQ) analysed risk from severe wind events in a marginal tropical cyclone (TC) region with a large exposed population, and historical severe thunderstorm and TC impacts. SWHA-SEQ was a collaborative effort bringing together 15 partners across government, academia and the insurance sector to improve the collective understanding of wind risk in the region and inform future strategies to reduce this risk, in the context of climate change, urban planning and socio-economic status of the population. </div><div>The project involved enhancing the understanding of hazard, exposure and physical vulnerability to strengthen the comprehension of risk, including local-scale wind hazard from thunderstorm and TC wind gusts, and a semi-quantitative analysis of future wind hazard. Structural characteristics of residential housing stock were updated through a combination of street surveys, national databases of built assets and insurance portfolio statistics. Vulnerability models for residential houses including retrofitted models for 5 common house types were developed, alongside identification of key vulnerability factors for residential strata buildings.</div><div>Local governments are building on the outcomes of the project, with the City of Gold Coast using the project outcomes as the key evidence base for a A$100m investment over 7 years to advocate for uplift of building design criteria, targeted community engagement and resilience of City-owned infrastructure. Other local governments have conducted specific exercises exploring how they would manage a severe TC impact. The investments and activities directly flowing from SWHA-SEQ are testament to the partner engagement through the project. Presented at the 2024 Symposium on Hurricane Risk in a Changing Climate (SHRCC2024)

The Tropical Cyclone Scenario Selection tool enables users (e.g. emergency managers, engineers, researchers, etc.) to query the catalogue of tropical cyclone scenarios, developed as part of the 2018 Tropical Cyclone Hazard Assessment (TCHA18). The TCHA18 catalogue is comprised of 10,000 simulated years of tropical cyclone activity in the Australian region, amounting to over 160,000 tropical cyclone events. Using the search tools, the tracks and wind fields of individual events affecting a location or region can be discovered and explored. The returned scenarios are retrieved from a catalogue of synthetic tropical cyclones and can queried within the map and/or downloaded in various formats for follow-on analysis.

This dynamic dataset is composed of data layers representing the potential damage arising from the impacts of Tropical Cyclone (TC) related winds on residential houses. The impacts are determined using information on the forecast track of the TC issued by the Bureau of Meteorology, nationally consistent exposure (residential building) and vulnerability (likely level of damage) information maintained by Geoscience Australia. The tracks are based on the content of Technical Bulletins issued by the Bureau of Meteorology’s Tropical Cyclone Warning Centres every 6 hours for active TCs in the Australian region. As such, information is generated intermittently, depending on the occurrence of TCs. The tracks are a forecast only, so do not include past position information of the TC. Forecasts may extend up to 120 hours (5 days) ahead of the forecast time. A wind field around each track is simulated using Geoscience Australia’s Tropical Cyclone Risk Model (TCRM, https://pid.geoscience.gov.au/dataset/ga/77484). This provides an estimate of the maximum gust wind speed over open, flat terrain (e.g. airports). Local effects such as topography and land cover changes are incorporated via site wind multipliers (https://pid.geoscience.gov.au/dataset/ga/75299), resulting in a 0.2-second, 10-m above ground level wind speed, with a spatial resolution of approximately 30 metres. The impacts are calculated using Geoscience Australia’s HazImp code (https://pid.geoscience.gov.au/dataset/ga/110501), which utilises the National Exposure Information System building data and a suite of wind vulnerability curves to determine the level of damage sustained by individual buildings (a damage index). The damage index values are aggregated to Australian Bureau of Statistics Statistical Area Level 1 regions, and can be assigned a qualitative damage description based on the mean damage index.

<div>To set out how Geoscience Australia is meeting its vision for the Exploring for the Future program, we have summarised the ways our scientific activities, outputs and intended outcomes and impacts are linked, using the Impact Pathway diagram. This updated brochure includes program impact infographics.</div>