Improving Australia’s flood record for planning purposes – can we do better?

ABSTRACT

Extreme rainfall is projected to increase with climate change, but the impact of climate change on floods is uncertain. Infrastructure design based on information available from short gauged time series (typically ~30 – 80 years) may not take account of the full range of possible flood events, or be suitable for identifying non-stationarity. Australian palaeoflood and palaeo-hydroclimate records drawn from a wide variety of natural archives and documentary sources suggest that Australia has been subjected to larger flood events in the past; a pluvial period for eastern Australia in the eighteenth Century is particularly note-worthy. If the current infrastructure is inadequate for past floods, it is unlikely it will adequately mitigate future floods. We discuss how improved awareness, and incorporation, of palaeoflood records in risk estimates could help guide infrastructure planning and design, flood event prediction and inform flood mitigation policy. This is particularly relevant for Australia with its notoriously variable hydroclimate.

KEYWORDS:

• Floods
• palaeofloods
• infrastructure design risk

Acknowledgments

This paper began its life at a workshop, jointly organised by Rob Vertessey, Rob Argent, Robert Wasson and Pandora Hope at the Bureau of Meteorology in Melbourne in August 2016. Records indicate that the following people attended the workshop: Rob Argent, Claire Cass, Graham Hawke, Peter May, Scott Power, Harald Richter, Tas van Ommen, Chris Thompson, Tim Hammond, Ben Henley, Janice Green, Eun Pa Lim, Joëlle Gergis, Prasantha Hapuarachchi, Jason Roberts, Anthony Kiem, Mandy Freund, Natasha Ballis, Tim Hammond, John Helstrom, Ian Goodwin, Lim Han She, Julien Lerat, Jonathan Nott, Doerte Jakob, Ailie Gallant, Duncan Ackerley, Anthony Worby, Rob Vertessey, Robert Wasson, Pandora Hope, Josephine Brown, Daryl Lam, Kathryn Allen. We thank the Bureau for its financial and logistical support and also the financial support of the Ministry of Education of the Government of Singapore for the attendance of RJW at the workshop. KA’s attendance at the workshop was supported by LP12020811. Pauline Treble provided valuable input about speleothem records, and we thank Rory Nathan for advice on an earlier draft of the manuscript. We also thank three anonymous reviewers for their constructive comments that helped improve this work.

Supplemental material

Supplemental data for this article can be accessed here.

Additional information

Funding

osephine Brown received support from the Australian Research Council Centre of Excellence for Climate Extremes.

Notes on contributors

KJ Allen

KJ Allen is a dendrochronologist working as a Research Fellow at the University of Melbourne. She completed her PhD at the University of Tasmania, looking at the dendroclimatological potential of a Tasmanian endemic species. Since completing her PhD she has worked as a teacher, consultant and in local government (water). Returning to an academic research role in 2008, she began developing additional tree-ring chronologies from both northern and southern Australia. Her interests include the development of new types of tree-ring chronologies based on novel wood properties, Australian hydroclimate history, the expansion of the Australasian tree-ring network, and research into techniques suitable for developing dated but non-annual records from trees.

P Hope

P Hope is an authority on the climate of Australia, working in the research division of the Australian Bureau of Meteorology. She is particularly interested in climate variability, change and extremes and what drives those.  Her interest in palaeoclimate includes a close examination of the variability of ENSO across reconstructions and simulations over the Last Millennium. Her PhD work examined Australia’s weather and climate at the Last Glacial Maximum.  More recent work includes attributing the drivers of individual climate extreme events, such as record warm months, or the wettest month on record in the Murray Darling Basin. She leads the Bureau of Meteorology’s contribution to the Victorian government’s Victorian Water and Climate Initiative and is the deputy lead on the project on climate variability and extremes under the Earth Systems and Climate Change hub of the Australian Government’s National Environmental Science Programme.

D Lam

D Lam Prior to his PhD research on Palaeoflood Reconstruction in Southeast Queensland at the University of Queensland, Daryl was a Research Associate in the National University of Singapore, working across various research projects across the realm of Physical Geography. These include urban storm water quality, tropical freshwater swamp hydrology and palaeofloods hydrology. Since the completion of his PhD, he has worked as an environmental consultant and is currently a waterway scientist dealing with palaeoflood reconstruction, and fluvial geomorphological aspects of managing waterways and flood mitigation. In addition, he is working consciously to communicate the science and value of palaeoflood hydrology beyond the academic community. In particular, he is very keen to see the integration of science and engineering through the use of palaeoflood records to improve flood mitigation.

JR Brown

JR Brown‘s research interests include past and future tropical climate variability and change, with a focus on monsoons, El Nino-Southern Oscillation and tropical rainfall. She uses global climate models to investigate changes in climate over a range of time scales, including the period since the Last Glacial Maximum and past analogues of a future warmer climate such as the Pliocene, as well as comparing palaeoclimate simulations with future climate projections. She completed her PhD in 2004 at the University of Melbourne and was a postdoctoral research fellow at the University of Reading, UK, from 2004-2006, and then at Monash University from 2006-2009. From 2009-2019 she was a research scientist at the Bureau of Meteorology, contributing to the development of climate projections for Australia and Pacific Island nations. In March 2019 she joined the University of Melbourne as a lecturer in palaeoclimate modelling.

RJ Wasson

RJ Wasson Before joining the National University of Singapore (NUS) in 2011 Professor Wasson was Director of the Centre for Resource and Environmental Studies, Dean of Science and Head of the Department of Geography and Human Ecology at the Australian National University, then Deputy Vice Chancellor Research and International at Charles Darwin University, Australia. He has taught and researched at Sydney University, Macquarie University, University of Auckland, Monash University, and the Australian National University. He was trained in geomorphology and his research interests are: Quaternary palaeoenvironmental reconstruction; causes of change in river catchments; environmental history; extreme hydrologic events in the tropics; cross-disciplinary methods; and the integration of science into public policy. He has done research in Australia, New Zealand, Indonesia, Timor Leste, Malaysia, India, Nepal, Pakistan, China, Myanmar and Thailand. From 2011 to 2018 he was a Senior Research Fellow in the Institute of Water Policy at the Lee Kuan Yew School of Public Policy at NUS where he focused on flood risk in relation to climate change, human vulnerability to floods over long periods in India and Thailand, and the political economy of disaster management in India and Thailand. He is currently an Adjunct Professor at JCU and Emeritus at ANU.