Storm Tide Recurrence Intervals – A Statistical Approach Using Beach Ridge Plains in Northern Australia

The marine inundation generated by Tropical Cyclone Yasi, north Queensland, February 2011, flooded at least 130 beachfront homes and many commercial businesses, becoming the most substantial marine inundation impact in Australia's modern history. As a consequence, guidelines for building in storm tide impact areas have been developed and discussions are beginning on whether Australia needs a national standard for buildings impacted by these events. Central to this will be determining which areas of coastal land need to be subjected to the standard, and this will likely be based upon the magnitude of a particular return interval event. The veracity of the current method for determining these return intervals is difficult to determine as there has been no objective way to assess the accuracy of this approach. One such method is developed here – applying extreme value theory statistics to millennial scale sedimentary records of tropical cyclone marine inundations. The approach is applied to a 5000‐year‐long beach ridge record of tropical cyclone inundations near Tully Heads and the results suggest that the inundation generated by Tropical Cyclone Yasi here had a return interval of approximately 1000 years. This is a substantially lower figure than the approximately 5000‐year return interval suggested by the currently accepted approach. Irrespective of which method is more accurate, the marine inundation generated by Yasi was a very rare event and one that may become more common under a future altered climate.     

Ageing in remote and cyclone‐prone communities: geography,policy, and disaster relief

Focusing on the experience of independent‐living older adults, this study explored how those in regional Australian coastal communities have coped with repeated natural disasters. Using an exploratory, mixed‐method, and phenomenological approach, an array of non‐probability snowballing techniques was used to seek participation from residents aged 65 years or more, and from emergency services officers, disaster managers, and community health care providers located in regional communities affected by Cyclone Larry (2006) and Cyclone Yasi (2011). The research found that post‐disaster political decisions have had a negative long‐term impact on local economies, causing outmigration by those seeking employment, and resulting in many elderly residents facing a future without family support. As government policies encourage ageing‐in‐place by providing subsidised in situ care, increasingly older adults are remaining in exposed vulnerable locations, reliant on authorities for their survival both day‐to‐day and during an emergency. Findings also uncovered inconsistent disaster management policies between neighbouring local government councils and an unrealistic reliance on in situ care organisations by disaster managers during preparation and recovery stages of a natural hazard. These results highlight the need for those charged with emergency management to reassess both the future natural hazard adaptive capacities of ageing regional communities and policy responses to such challenges.     

Securing Landscape Resilience to Tropical Cyclones in Australia's Wet Tropics under a Changing Climate: Lessons from Cyclones Larry (and Yasi)

Tropical cyclones are part of the ecosystem dynamics of rainforests in the Wet Tropics of Australia, and intact forest areas show remarkable ability to recover from cyclonic disturbance. However, forest remnants, littoral rainforests, and riparian vegetation have been shown to be particularly susceptible to cyclonic winds and post‐disturbance weed invasion with consequences for their long‐term conservation values. I evaluate the frequency and intensity of tropical cyclones impacting the Wet Tropics region since records began in 1858. The recent Category 4 cyclones featured in this study, Larry and Yasi, had return intervals of about one in 70 years. I then discuss the natural resource management (NRM) lessons from Cyclone Larry and put forward practical recommendations on how authorities should deal with natural resources in the clean‐up and recovery phases. I argue that natural resources must be treated as valuable commodities by including their protection and rehabilitation in the same way that human livelihoods, infrastructure and industry are covered in disaster management planning. This requires NRM issues to be included in disaster response policy and legislation, together with ensuring that structures are in place to mitigate the effects of cyclones on natural resources. There is a general consensus that tropical cyclone intensity will increase under climate change while frequency will decrease slightly. This has profound implications for the long‐term sustainability of ecosystems in the Wet Tropics. There is a real risk of a phase shift to vegetation types dominated by disturbance species, including weeds, at the expense of cyclone intolerant species. It is therefore important that we begin to build more cyclone resilient landscapes to reduce the vulnerability of our remaining rainforest habitats and primary production systems. Securing landscape resilience requires greater NRM investment in key areas, including landscape connectivity, river repair, protecting coastal assets and cyclone resilient farms. While climate change poses a long‐term threat to the rainforests of the region, we need to focus on more immediate pressures affecting our remaining biodiversity, notably clearing of native habitat, habitat fragmentation and degradation, and biosecurity issues.