@article {bnh-7922, title = {Improving the resilience of existing housing to severe wind events - final project report}, number = {656}, year = {2021}, month = {03/2021}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This BNHCRC project titled:\  Improving the resilience of existing housing to severe wind events prescribes practical structural retrofits that will make improvements to the performance of Pre-80s (Legacy) houses in windstorms as well as measures to reduce damage and loss to contemporary houses.

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe windstorms have typically shown that houses built prior to the mid-1980s in Australia perform worse than houses constructed to contemporary building standards, during windstorms. Given that these older houses are a significant proportion of the housing stock, practical structural upgrading based on the latest research may improve performance of housing and the economic and social wellbeing of a community.

Some details for structural retrofitting currently exist, but their uptake is limited, and there is also evidence that these are not carried out when houses require repairs following severe storms. Therefore, the issues of retrofitting legacy housing, including feasibility and benefit-cost are analysed in this project.

The primary objective of this study was to identify vulnerable legacy house types across Australia and develop cost-effective retrofits for mitigating damage during windstorms. These evidence-based strategies will (a) aid policy formulation and decision making by Government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the industry for retrofitting typical at-risk houses in Australia. The main aims were to:

This report presents an overview of the research approach used for this project including the selection of house types, the development of the VAWS software and the Internet-based guidelines. A case study is presented of the vulnerability and benefit cost assessment of one of the selected house types, with the complete set of results presented in the Appendices. These results show that tile roofed houses in cyclonic regions of Australia benefit the most from retrofitting for severe wind events. The benefit-cost ratios for these tile roof houses and other house types are expected to improve when accounting for intangible costs, which are currently not included in the analyses presented in this report. In addition, examples of the impacts and utilisation of this project including the Queensland Government Housing Resilience Program are also presented.

}, keywords = {cyclone, events, existing housing, resilience, severe, wind}, issn = {656}, author = {John Ginger and Korah Parackal and David Henderson and Martin Wehner and Hyeuk Ryu and Mark Edwards} } @article {bnh-7006, title = {Disasters and economic resilience: the income effects of the Cyclone Oswald 2013 on small business owners}, number = {581}, year = {2020}, month = {06/2020}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

"With five events in two years and the recently released Climate Commission Report that indicates our region can expect higher risk of heavy rainfall, there is a responsibility to at least identify the real cost to the community of flood events"\  {\textendash} Mark Pitt, CEO, North Burnett Regional Council (2013)

Small businesses are regarded as the backbone of Australia{\textquoteright}s economy, forming up to 98\% of Australian businesses and employing around 44\% of Australia{\textquoteright}s private sector workforce (Australian Bureau of Statistics, 2018). In some sectors like agriculture and construction, small businesses represent over 70\% of all businesses (Gilfillan, 2018).

Beyond employment, small businesses are integral to the social fabric of their communities, supporting local initiatives and providing important physical places for community members to socialise and engage with each other. This is especially true for regional areas with tight-knit communities.

Despite their economic importance, little empirical research has been done to understand the impact of natural disasters[1] on small businesses, and the efficacy of government assistance programs in promoting their recovery.

To that end, the Disasters and Economic Resilience: The income effects of Cyclone Oswald 2013 on Small Business Owners {\textendash} a case study on the Burnett River Catchment Area report explores the impact of ex-Tropical Cyclone Oswald 2013 on the incomes of small business owners residing in the four Burnett River Catchment local government areas (LGAs) depicted in FIGURE 1.

From 22 to 29 January 2013, Category 1 ex-tropical Cyclone Oswald moved across parts of Queensland and New South Wales, causing severe storms, flooding and tornadoes. The associated flooding and extreme weather events were declared a disaster in 53 Queensland LGAs, with the most devastating felt in the Bundaberg and North Burnett regions, damaging key infrastructure including sewerage systems and economically important assets including ports and road networks relied on by agricultural and manufacturing enterprises in the area. The record flooding in Bundaberg forced the evacuation of over 7,500 residents and damaged over 2,000 homes.

Thus, the flooding events associated with Cyclone Oswald that occurred in this region present a unique opportunity to causally investigate the impacts of a major disaster on small businesses in a regional community with an important agricultural base.

Isolating the effects of the floods from other shocks that hit the Burnett River catchment LGAs is challenging. The report pinpoints the income effects of Cyclone Oswald 2013 by using a difference-in-differences modelling approach. This approach compares the income changes of small business owners living in the Burnett River Catchment LGAs (treatment group) with those living in the comparable Richmond Valley LGAs in New South Wales (control group). Because of their comparability, it is the control group which provides us with the income path that would have occurred for the Burnett small business owners had the floods not happened, and thus enable us to compute any income deviations (losses or gains) arising from the associated flooding events.\ 

The report utilises the Australian Census Longitudinal Dataset (ACLD), which provides a unique opportunity to robustly examine the flood{\textquoteright}s impacts. Our results are net results, post any disaster relief and recovery efforts; are relative to our baseline year (2011); and are compared to our control group. As the Census date allow us to explore the effects up to three years post Cyclone Oswald, we define our 2011-2016 results as medium-term results.

}, keywords = {cyclone, disasters, economic resilience, income effects, small businesses}, issn = {581}, author = {Mehmet Ulubasoglu} } @article {bnh-6868, title = {Vulnerability assessment of bridges subjected to extreme cyclonic events}, journal = {Natural Hazards}, year = {2020}, month = {04/2020}, abstract = {

Over the past few years, Queensland in Australia has suffered from a number of severe tropical cyclones, the most recent one being Marcia, which took place in 2015. Damage bill of Cyclone Marcia exceeded $50 million which included the cost of repairing a number of damaged road structures. Failure of road structures such as bridges isolates communities from accessing essential services and commodities. This necessitated a methodical approach to evaluate the failure of bridges to improve their resilience and provide base knowledge for developing emergency maintenance response. Although there are several methods available to evaluate the vulnerability of bridges, fault tree analysis (FTA) was selected in this study by considering its positive attributes over the other methods. FTA was used to estimate the probabilities of failure of main components (superstructure and substructure) and elements of timber and concrete bridges. Secondary data (level 1 and level 2 bridge inspection reports from Transport Main Roads in Rockhampton) before and after the Cyclone Marcia were used in conjunction with expert advice to construct fault trees for both timber and concrete bridges. Potential failure mechanisms were observed, and the degree of susceptibility of main components of timber and concrete bridges to cyclonic events was evaluated. This research was based on selected bridges under specific cyclone in one region, which is a limitation of the study. Few other case study bridges subjected to cyclonic events can be used to strengthen the understanding of the complete dynamics of the bridge failure under these extreme events.

}, keywords = {bridge failure, cyclone, fault tree analysis, preventative maintenance, Vulnerability}, doi = {https://doi.org/10.1007/s11069-020-03931-y}, url = {https://link.springer.com/article/10.1007/s11069-020-03931-y$\#$citeas}, author = {Thilini Pathiranage and Weena Lokuge} } @article {bnh-5929, title = {Economics of natural hazards annual report 2018-2019}, number = {512}, year = {2019}, month = {09/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Our project aims to provide information on the economic, social and environmental impacts of natural hazards (tangible and intangible), in order to help hazard managers in their decision making. We investigate the impacts of hazard mitigation on intangible (non-market) values, to shed light on the real (total) costs and benefits of natural hazards.

Our main focus is on developing tools and materials that will provide natural hazards managers with information on the value of mitigation and how intangible (non-market) values affect the costs and benefits of mitigation activities.
Our project will have 4 key outcomes:

  1. Provide an online platform for the intangible values database (called the Value Tool for Natural Hazards). The tool will be updated and maintained beyond the project so that managers can easily integrate intangible values in their analyses.
  2. Fill major knowledge gaps identified in the literature on intangible values that are affected by the management of natural hazards and improve the value tool with this new knowledge.
  3. Develop a Quick Economic Analysis Tool for the evaluation of the (tangible and intangible) costs and benefits of mitigation options that enables managers to conduct economic analyses in weeks rather than months.
  4. Create a Free Online Course on the application of economics to the assessment of natural hazard management options.

This year, we have progressed in the 4 outcomes outlined above:

  1. A website has been created for the Value Tool. Both the database and the guidelines can now be downloaded from http://valuetoolnaturalhazards.com. As per the agreement between UWA and BNHCRC, the tool will be freely accessible to end-users and external users. The website also includes the relevant disclaimer information and instructions that users of the tool must agree to comply with.
  2. A survey instrument has been designed and road-tested in a focus group for the original non-market valuation study. The next step in this process will be to test the survey in the Shire of York (WA), where we will estimate non-market values associated with cultural heritage and mental health.
  3. The draft (Beta) version of the Quick Economic Analysis Tool (QEAT) has been completed. QEAT is currently being improved to include an easy-to-use sensitivity analysis, to be able to perform the analysis of several management options concurrently and to include a summary dashboard where all results are summarised in an easy-to-read manner. These additions are key aspects that our end-users have mentioned in the past as important to include in a tool such as this one. The Tool now needs to be validated with case studies.
  4. Equipment for creating the online videos is being purchased (e.g. green screen for background, microphone and tripod for computer). Filming of the videos will commence in July 2019.

The utilisation outputs from our project this year involved the development and distribution of tools that help natural hazard managers integration intangible (non-market) values in their decision making. The Value Tool for Natural Hazards and the accompanying guidelines are now available online and can be easily downloaded by end-users of the BNHCRC or other organisations. The Beta version of the Quick Economic Analysis Tool (QEAT) is in the process of being improved to include key aspects that were highlighted by end-users as important to include in a tool as this one.

This year there were 4 publications from the project: 3 peer-reviewed and one non-peer reviewed (see Project Publications 2018-2019 section below).

}, keywords = {Bushfire, cost-effective, cyclone, earthquake, economics, Emergency management, Flood, Natural hazards, risk management}, issn = {512}, author = {Veronique Florec and Abbie Rogers and Atakelty Hailu and David J Pannell} } @article {bnh-6333, title = {Model for assessing the vulnerability of Australian housing to windstorms - VAWS}, number = {529}, year = {2019}, month = {12/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Modelling the vulnerability of houses in windstorms is important for insurance pricing, policy-making, and emergency management. Models for Australian house types have been developed since the 1970s, and have ranged from empirical models to more advanced reliability based structural engineering models, which provide estimates of damage for a range of wind speeds of interest. This report describes the development of a software program: Vulnerability and Adaption to Wind Simulation (VAWS), which uses probability based reliability analysis and structural engineering for the loading and response coupled with an extensive test database and field damage assessments to calculate the damage experienced by selected Australian house types.\ \ 

}, keywords = {building resilience, cyclone, Emergency management, engineering, severe wind, wind modelling}, issn = {529}, author = {Korah Parackal and Martin Wehner and Hyeuk Ryu and John Ginger and David Henderson and Mark Edwards} }