A multi-hazard and exposure analysis of Asia. A GIS study that incorporates regional data for: landslide, tsunami, earthquake, tropical cyclone, volcanic, drought and flood hazard.

A probabilistic tsunami hazard assessement (PTHA) was developed for the island of Tongatapu, All modelled tsunamis were initiated by hypothetical thrust earthquakes on the nearby Kermadec-Tonga subduction zone. We provide raster outputs containing the inundation depth with an estimated 10% and 2% chance of being exceeded in 50 years, as well as the code used to perform the analysis [both available here: https://github.com/GeoscienceAustralia/ptha/tree/master/misc/probabilistic_inundation_tonga2020].

University of Newcastle researchers captured media attention in 2017 with the release of a study modelling tsunami risk for the city of Sydney. The study considered a range of scenarios from minor disruptions through to rare, one-in-5000-year disasters. It’s possible the study made headlines in part for the novelty factor. This is not to say Australians are flippant about tsunamis; as a nation, we have grieved the traumatic impact of tsunamis in our region. We just don’t think it will happen to us. However, the science says otherwise. The historical and prehistorical record indicates that tsunamis have affected Australia in the past and could do so again. To Australia’s north and east lie thousands of kilometres of tectonic plate boundaries, where undersea earthquakes could generate tsunamis that reach Australia in a matter of hours. Given half the Australian population lives within 10 kilometres of a coastline – not to mention the scores of interstate and international visitors to our beaches – it’s imperative we take tsunami planning seriously. That’s why the Australian Institute for Disaster Resilience (AIDR) partnered with the Australian Tsunami Advisory Group (ATAG) to revise and refresh national guidance for tsunami emergency planning in Australia. ATAG is the leading national group for tsunami capability development, bringing together the expertise of policymakers, scientists and emergency services practitioners from around Australia. The review produced the Tsunami Emergency Planning in Australia Handbook, an authoritative resource for emergency managers, local and state governments, port authorities and commercial operators in coastal areas. Replacing its 2010 predecessor, Manual 46: Tsunami Emergency Planning in Australia, the handbook was published on 5 November 2018 to mark the United Nations World Tsunami Awareness Day. In clear, accessible language, the handbook outlines the causes and characteristics of tsunamis, separating fact from fiction and highlighting key terms. It introduces planners to both ‘Marine Threat’ and ‘Land Inundation Threat’ – key categories in the tsunami warnings framework – and explores the corresponding planning considerations for coastal communities as well as more transitory ‘maritime’ communities – including fishers, boaters and swimmers. Maritime communities also encompass a range of commercial and government activities, including offshore oil and gas enterprises, military exercises and tourism. The handbook steps users through the responsibilities, processes and warning types that comprise the Australian Tsunami Warning System that was established by the Australian Government after the 2004 Indian Ocean tsunami. ATAG has actively contributed to the management of tsunami risk by promoting research, knowledge management and education. In 2018, ATAG also partnered with AIDR to develop the Tsunami hazard modelling guidelines that represent the most up-to-date view of tsunami hazard nationally. A key companion to the revised handbook, the guidelines present a principles-based approach to developing tsunami hazard information for different purposes; from emergency management to infrastructure development and insurance. The guidelines don’t dictate the use of a particular software; they ask questions to support cooperative approaches between scientists and end users. As for the handbook, stakeholder consultation was key to the development of the Tsunami hazard modelling guidelines. Geoscience Australia, an ATAG member, led the process in partnership with public and private sector representatives and with Commonwealth funding support through Emergency Management Australia. The guidelines emerged from a community-driven development process that engaged different end users and recognised the impact of a range of factors on modelling approaches and decisions (such as the use case and available data). A workshop held in Canberra in 2017 was a key step, bringing together tsunami modelling experts from government, industry and academia. The handbook and companion guidelines are complimented by the Probabilistic Tsunami Hazard Assessment from Geoscience Australia. This resource informs local tsunami inundation modelling, which feeds into evacuation planning and community safety. The Tsunami handbook is also supported by Tsunami: The Ultimate Guide – an online learning resource developed collaboratively by ATAG and led by Surf Life Saving Australia. The guide raises tsunami awareness through the education of school-aged children and achieved a highly commended award in the 2014 Resilient Australia Awards. The Tsunami Emergency Planning in Australia Handbook and the suite of companion resources is part of the Australian Disaster Resilience Handbook Collection. The Handbook Collection represents nationally agreed principles on a range of salient disaster resilience themes; supporting organisations across sectors to adopt best-practice approaches aligned to national policy.

The service contains the Australian Coastal Geomorphology Environments, used to support a national coastal risk assessment. It describes the location and extent primary geomorphological environments (both dispositional and erosional) present along the Australia coast and the processes acting on the features within. It is cached service with a Web Mercator Projection.

The Geological Survey of Canada's 5th Generation seismic hazard model for Canada forms the basis for the seismic design provisions of the 2015 National Building Code of Canada (NBCC). We deaggregate the seismic hazard results for selected cities to help understand the relative contributions of the earthquake sources in terms of distance and magnitude. Deaggregation for a range of probabilities and spectral accelerations (Sa) from 0.2 to 10.0 seconds is performed to examine in detail the hazard for two of Canada's largest urban centres at highest risk, Vancouver in the west and Montréal in the east. A summary table of deaggregated seismic hazard is provided for other selected Canadian cities, for Sa(0.2), Sa(2.0) and peak ground acceleration (PGA) at a probability of exceedence of 2%/50 years. In most cases, as the probability decreases, the hazard sources closer to the site dominate. Larger, more distant earthquakes contribute more significantly to hazard for longer periods than shorter periods. The deaggregations allow better-informed choices of scenario events and for the selection of representative time histories for engineering design.

This paper presents a model to assess bushfire hazard in south-eastern Australia. The model utilises climate model simulations instead of observational data. Bushfire hazard is assessed by calculating return periods of the McArthur Forest Fires Danger Index (FFDI). The return periods of the FFDI are calculated by fitting an extreme value distribution to the tail of the FFDI data. The results have been compared against a spatial distribution of bushfire hazard obtained by interpolation of FFDI calculated at a number of recording stations in Australia. The results show that climate simulations produce a similar pattern of bushfire hazard than the interpolated observations but the simulated values tend to be up to 60% lower than the observations. This study shows that the major source of error in the simulations is the values of wind speed. Observational wind speed is recorded at a point-based station whilst climate simulated wind speed is averaged over a grid cell. On the other hand FFDI calculation is very sensitive to wind speed and hence to improve the calculation of FFDI using climate simulations it is necessary to correct the bias observed in the simulations. A statistically-based procedure to correct the simulation bias has been developed in this project. Bias-corrected calculation of FFDI shows that the major bushfire hazard in south-eastern Australia is in the western parts of SA and NSW; and in south-western Tasmania.

Strong surface wind gusts and heavy rain are meteorological hazards that are predominantly produced by storms such as east coast lows, tropical cyclones or thunderstorms. Interest in these hazards from a response agency point of view lies in their impact on the natural and built environment. At present, weather forecast models still predict mostly 'raw' meteorological output such as surface wind speeds at certain times, or rain accumulations over a specified period. This model output needs to be combined with exposure and vulnerability information to translate the forecast hazard into predicted impact. The Bushfire and Natural Hazards CRC project Impact-based forecasting for the coastal zone: East-Coast Lows attempts to demonstrate a pilot capability to deliver impact forecasts for residential housing from an ensemble of weather prediction models runs. The project is a collaborative effort between the Australian Bureau of Meteorology and Geoscience Australia. The project is initially focusing on the wind and rainfall impact from the 20-22 April 2015 east coast low event in NSW. The wind and rainfall hazard data are provided by a 24-member ensemble of the ACCESS model on a 1.3 km grid, with damage data acquired from NSW State Emergency Services (SES) and the Emergency Information Coordination Unit (EICU) for the 2015 event. We will show that the multi-hazard nature of an east coast low event makes attributing the observed building damage to a single hazard difficult. Wind damage to residential housing in this case is largely due to tree fall. This 'damage-by-intermediary' mechanism requires not just the knowledge of building properties in an exposed area, but also additional knowledge of the surrounding vegetation and its response to strong winds. We will discuss enhancements to the SES/EICU damage survey templates that would lead to improvements in the development of the hazard-damage relationships.

Geoscience Australia has recently released the 2012 version of the National Earthquake Hazard Map of Australia. Among other applications, the map is a key component of Australia's earthquake loading code AS1170.4. In this presentation we provide an overview of the new maps and how they were developed. The maps take advantage of significant improvements in both the data sets and models used for earthquake hazard assessment in Australia since the map currently in AS1170.4-2007 was produced. These include: - An additional 20+ years of earthquake observations - Improved methods of declustering earthquake catalogues and calculating earthquake recurrence - Ground motion prediction equations (i.e. attenuation equations) based on observed strong motions instead of intensity - Revised earthquake source zones implementing a multi-layer model - Improved maximum magnitude earthquake estimates based on palaeoseismology - The use of open source software for undertaking probabilistic seismic hazard assessment, which promotes testability and repeatability Hazard curves are presented for a range of response spectral acceleration (RSA) periods between 0.0 and 1.0 s and for return periods between a few hundred to a few thousand years. These curves and maps are compared with the current earthquake hazard values in AS1170.4-2007. For a return period of 500 years, the hazard values in the 0.0 s RSA period map are generally lower or the same as the hazard factor values in the AS1170.4 map. This is also true for most of the other RSA periods up to 1.0s for the cities in Australia with Darwin being the main exception. By contrast, the hazard for return periods above 1000 years is higher than the values derived from the tables in AS1170.4 for all RSA periods.

Tropical cyclone return period wind hazard layers developed using the Tropical Cyclone Risk Model. The hazard layers are derived from a catalogue of synthetic tropical cyclone events representing 10000 years of activity. Annual maxima are evaluated from the catalogue and used to fit a generalised extreme value distribution at each grid point.

The Flood Study Summary Services support discovery and retrieval of flood hazard information. The services return metadata and data for flood studies and flood inundation maps held in the 'Australian Flood Studies Database'. The same information is available through a user interface at http://www.ga.gov.au/flood-study-web/. A 'flood study' is a comprehensive technical investigation of flood behaviour. It defines the nature and extent flood hazard across the floodplain by providing information on the extent, level and velocity of floodwaters and on the distribution of flood flows. Flood studies are typically commissioned by government, and conducted by experts from specialist engineering firms or government agencies. Key outputs from flood studies include detailed reports, and maps showing inundation, depth, velocity and hazard for events of various likelihoods. The services are deliverables fom the National Flood Risk Information Project. The main aim of the project is to make flood risk information accessible from a central location. Geoscience Australia will facilitate this through the development of the National Flood Risk Information Portal. Over the four years the project will launch a new phase of the portal prior to the commencement of each annual disaster season. Each phase will increase the amount of flood risk information that is publicly accessible and increase stakeholder capability in the production and use of flood risk information. flood-study-search returns summary layers and links to rich metadata about flood maps and the studies that produced them. flood-study-map returns layers for individual flood inundation maps. Typically a single layer shows the flood inundation for a particular likelihood or historical event in a flood study area. To retrieve flood inundation maps from these services, we recommend: 1. querying flood-study-search to obtain flood inundation map URIs, then 2. using the flood inundation map URIs to retrieve maps separately from flood-study-map. The ownership of each flood study remains with the commissioning organisation and/or author as indicated with each study, and users of the database should refer to the reports themselves to determine any constraints in their usage.