Understanding floods

Graphic: Global importance of floods and storms

Flooding occurs when excess water from high rainfall events cannot be absorbed into the landscape. This may be due to extreme rainfall events, (as with cyclones), changes in land cover and vegetation across the river catchment, and saturation of soils and aquifers.

In an attempt to predict potential flood events, and thus mitigate their impacts, hydrometeorological models are used to estimate where excess water is likely to flow.  As our understanding of meteorological events and hydrological processes improves, our ability to predict flooding improves, but this is still an imperfect science.

As a result of this still imperfect science of flood estimation and prediction, providing assistance to communities in flood preparedness is vital. Developing techniques to reduce flood impacts is an important component in flood research, as is the development of adaptive approaches to flood engineering solutions.

Graph shows economic damage of floods from major events 1996-2016

Graph shows deaths caused by major floods 1911 - 1999

Ten years of Australian floods

February 2008 Mackay floods QLD
September 2010 Victorian floods VIC
March 2010 Queensland floods QLD
December 2010 Carnarvon/Gascoyne  WA
December 2010 - January 2011 Queensland floods QLD
January 2011 Victorian Floods  VIC
August 2011 Gippsland  VIC
February - March 2012 Eastern Australia  NSW, VIC, QLD
March 2012 Gippsland and Koowerup VIC
January – February 2013 Eastern Australia Floods  QLD, NSW
April 2015 Hunter Valley/Central Coast/Sydney  NSW
May 2015 South East Queensland Flash Floods QLD
June 2016 Tasmanian Floods TAS
September 2016 Central West and Riverina Floods NSW
February 2017 West Australian Floods WA
March - April 2017 East Australian Floods,Cyclone Debbie SEQ, N NSW
May 2018 Tasmanian Floods, Hobart TAS
Sources: Queensland Police Service, SES, BOM,  ABC News, Melbourne Herald Sun, The Daily Mail, the Guardian, The Courier Mail

A flooded street in Lismore NSW. Image courtesy M Kirby