Floodplain Manager November 2020


Australia’s 2020 State of the Climate Report has been released and reports that there has been a century long trend of increasing temperatures across Australia.  This has been accompanied by the north of the continent becoming wetter and the south of the continent drier.  The forecast is that these trends will continue, and rainfall events and tropical cyclones will become more intense.  So, while parts of the country may have less rain, they may get more floods.  These trends and forecasts are not new, but neither are they an aberration as some believe or hope.

International studies report there has been a 50% increase in the rate of sea level rise over the past ten years compared to longer term averages.  We also report forecasts of an increase in coincident coastal river flooding with storm surge due to climate change.  When these are combined with sea level rise, coastal populations are going to be severely impacted by the convergence of three adverse flood trends.  Australian analyses indicate that Sydney, Brisbane and Launceston will be hardest hit by these changes.

Other statistics in this edition are also sobering:

  • Worldwide, 54 million people are exposed to river floods each year with summer floods in Asia accounting for 63% of the casualties.
  • Every country has floods but 90% of the world’s flood-exposed population live in low- and middle-income countries.
  • Even in high income countries like the UK, new homes in economically declining areas are 10 to 13 times more likely to experience an increase in flood risk due to climate change than those in affluent areas.

The launch in November of the Australian Institute of Disaster Resilience’s Flood Planning for Disaster Resilience Handbook is therefore timely because we need to be looking carefully at ways of making existing and future development more resilient in all types of floods.

Steven Molino

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