Drought of knowledge on Australian natural hazards
Whenever droughts occur in Australia, our ability to monitor, attribute, forecast and manage them is shown to be insufficient. That is the conclusion of a a new study by Australian researchers undertaken through OzEWEX, and published in the journal Climatic Change. The study finds that, unlike for other hydroclimatic hazards, we currently have very limited ability to tell when a drought will begin or end. Hence our ability to manage this common hazard is highly limited.
Droughts are a recurrent and natural part of the Australian hydroclimate, with evidence of drought dating back thousands of years. Our knowledge of how droughts work, however, requires improvement if we are to get a better handle on the nature of this characteristically Australian hazard.
“Our understanding and management of drought relies heavily on what we see in the instrumental record, which means we’re lulled into a false sense of security that drought can’t exceed extremes we’ve seen in the past 50 – 100 years, but in fact, it has, and likely will again.” Anthony Kiem
In this recent research, led by University of Newcastle Hydroclimatologist Anthony Kiem, three key points of improvement are identified as future research focus areas. The areas identified for future research are:
- Better capacity to define and monitor drought characteristics (i.e. frequency, start, duration, magnitude, and spatial extent) to remove confusion between drought causes, impacts and risks and better distinguish between drought, aridity, and water scarcity due to over-extractions.
- More work to document historical (instrumental and pre-instrumental) variation in drought to better understand baseline drought characteristics, enable more rigorous identification and attribution of drought events or trends, inform/evaluate hydrological and climate modelling activities and give insights into possible future drought scenarios.
- Work to improve the prediction and projection of drought characteristics with seasonal to multi-decadal lead times and including more realistic modelling of the multiple factors that cause (or contribute to) drought so that the impacts of natural variability and anthropogenic climate change are accounted for and the reliability of long-term drought projections increases.
The general aim of the work was simply to get a better handle on what we know about drought in Australia, rather than what the impacts of drought are, and how we can improve this understanding to improve our ability to manage droughts. This work was required because the nature of historical and future changes to Australian drought and its drivers are poorly understood.
“With Australia’s European settlement, a lot of our planning and methods to combat drought are influenced by European practices. Australia’s climate is obviously very different to Europe’s, meaning, in a lot of cases, droughts are not properly understood or managed, and that we are not well-prepared for future changes to drought” Anthony Kiem
One of the most important issues identified by this research is the need for rigorous approaches to distinguish between correlation and causation with respect to drought, such as the question of whether increased temperatures or abnormally dry antecedent conditions are a cause or a sign of drought?
The authors note that the knowledge gaps, challenges and recommendations identified are relevant beyond the Australian context and it is hoped that this paper will contribute to a further understanding of drought in general.
The overarching purpose of this work is for it to act as a guide for directing future research with the ultimate goal of minimising the negative impacts of droughts when they inevitably occur.
Article: ‘Natural hazards in Australia: drought’, Kiem, A., Johnson, F., Westra, S., van Dijk, A., Evans, J., O’Donnell, A., Rouillard, A., Barr, C., Tyler, J., Thyer, M., Jakob, D., Woldemeskel, F., Sivakumar, B. and Mehrotra, R. , Climatic Change, doi: 10.1007/s10584-016-1798-7