Drought in Australia
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Drought in Australia is defined by rainfall over a three month period being in the lowest ten percent of amounts having been recorded for that region in the past.<ref name="BOMGlossaryDrought">Drought. Climate Glossary. Bureau of Meteorology (2006). Retrieved on 2006-11-13.</ref> This definition takes into account that low rainfall is a relative term and rainfall deficiencies need to be compared to typical rainfall patterns including seasonal variations. Much of Australia receives typically low rainfall. Historical climatic records are now sufficiently reliable to profile climate variability taking into account expectations for regions.<ref name="daffclimate">Our Natural Resources at a Glance - Climate. Department of Agriculture, Fisheries and Forestry (Australia) (2006). Retrieved on 2006-11-13.</ref> State Governments are responsible for declaring a region drought affected and the declaration will take into account factors other than rainfall.<ref name="BOMGlossaryDrought"/> The Australian federal Government provides drought assistance in exceptional circumstances through the Department of Agriculture, Fisheries and Forestry.<ref name="daffdrought">Drought and Exceptional Circumstances. Climate Impact Sciences Program. Department of Agriculture, Fisheries and Forestry (Australia) (2006). Retrieved on 2006-11-13.</ref>
Australian droughts are typically characterized by a water crisis in country towns, which often threatens millions of dollars worth of crops and limits drinking water for stock.
Authorities are forced to implement rationing schemes of dwindling water supplies when rainfall fails to fill reservoirs. The Federal government often has to subsidise farmers, whose income collapses during the dry spells.
In recent years large cities like Toowoomba and Brisbane have had water restriction implemented to save water as drought has reduced the inflow to dams which were built for water supply.
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[edit] Drought in the twentieth century
At the time of Federation, Australia suffered a major drought. There has been a number of years of below average rainfall across most of Australia before the drought. During the drought the wheat crop was "all but lost" and the Darling River nearly ran dry at Bourke, New South Wales. There was concern about Sydney's water supply.<ref name="BOM1902">The "Federation Drought", 1895-1902. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.</ref> In 1914-1914, Australia suffered a major drought which resulted in the failure of the 1915 wheat crop.<ref name="BOM14-15">The 1914-15 drought. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.</ref>
During World War II, eastern Australia suffered dry conditions which lasted from 1937 through to 1947 with little respite.<ref name="BOMww2">The World War II droughts 1937-45. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.</ref> From 1965-68 eastern Australia was again greatly affected by drought as conditions had been dry since 1957. This drought contributed to the 1967 Tasmanian fires in which 62 people died in one day and 1400 homes were lost.<ref name="BOM65-68">The 1965-68 drought. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.</ref> The drought in 1982-83 is regarded as the worst of the twentieth century for short-term rainfall deficiencies of up to one year and their overall impact. There were severe dust storms in north-western Victoria and severe bushfires in south-east Australia in February 1983 with 75 people killed.<ref name="BOM1982-83">Short but sharp - The 1982-83 droughts. Climate Education. Bureau of Meteorology. Retrieved on 2006-11-13.</ref>
A very severe drought occured in second half of 1991 <ref>Rankin, Robert. (1992) Secrets of the Scenic Rim. Rankin Publishers ISBN 0-95924-183-3 (page 151)</ref> which intensified in 1994 and 1995 to become the worst on record. This drought was influenced by a strong El Nino weather pattern and associated with high temperatures in July and August of 1995, the fifth year continuous year of drought in parts of Queensland. So many wheat and barley crops failed, about half the usual for that year, that grains had to imported from other states. <ref>Coleman, Matthew. Crops worth $50m lost"". The Courier Mail. 30 August 1995</ref>. The Darling River system collapsed during this drought.
[edit] Drought in the twenty first century
Around 2000 Australia was prone to wet weather brought on by La-Nina influenced weather patterns.
Then from 2003 a long, severe drought, again the worst on record<ref name="worst">"Rural News 03/09/2003: Worst drought on record", ABC, 2003-09-03. Retrieved on 2006-11-17.</ref> was experienced in many parts of Australia. In 2006 it was declared a 1000-year drought event<ref name="1000-year">"Australia's dry horrors 'worst for 1000 years'", The New Zealand Herald, 2006-11-08. Retrieved on 2006-11-17.</ref>. This drought appeared to trigger a collapse of the Murray-Darling River system, the countries largest.[citation needed]
[edit] Rainfall deficiencies in 2006
As at November 2006, the late-winter to mid-spring rainfalls had failed. The average rainfall in the state of South Australia was the lowest since 1900. Across Victoria and the Murray-Darling Basin the season was the second driest since 1900. New South Wales rainfall was boosted by above normal falls along the north coast of the state, however the state average rainfall for the season is the third driest since 1900. The situation has been exacerbated by temperatures being the highest on record since the 1950s.<ref name = "droughtstatemeentNov06">"Statement on Drought for the 3, 6, and 10-month periods ending 31st October 2006 - Drought intensifies over eastern and southern Australia as spring rains fail", Drought Statements, National Climate Centre, Bureau of Meteorology, 2006-11-03. Retrieved on 2006-11-13.</ref>
[edit] Responses
The current drought has changed the way Australia treats its water resources. Because of the long-term effects of the drought now showing, many state governments are attempting to "drought-proof" their states with more permanent solutions.
Australia in the past hundred years has relied solely on water from dams for agriculture and consumption. Now schemes like Grey-water water-recycling, government rebates for home-owners to install water tanks, and tougher restrictions on industries have come into effect.
The citizens of Toowoomba has voted on, and rejected, a referendum on using recycled sewerage water. Brisbane is set to be supplied via larger dams, a pipeline and possibly also recycling. A Desalination project has been initiated on the Gold Coast, Queensland, but plans for a similar project in Sydney were halted after public opposition and the discovery of underground aquifers. In November 2006 Perth will complete a seawater desalination plant that will supply the city with 17% of its needs.<ref>http://www.watercorporation.com.au/D/desalination.cfm</ref>
Most Australian mainland capital cities are facing major water crisis with less than 50% of water storages remaining. For example Melbourne has had rain up to 90% below the average for September and October 2006 compounding the problem of extremely low rainfall from the preceding winter months.[citation needed] Melbourne has been experiencing high temperatures throughout October causing the evaporation of water in dams and reservoirs, which has resulted in their levels falling by around 0.1% a day. As a result of all these factors Melbourne is now on higher water restrictions.
On Thursday 12th October 2006 Melbourne recorded its hottest October day in 92 years reaching 36.6 degrees celsius - a hot summer's day temperature in the middle of spring. On this particular day over 250 wildfires burnt throughout the state of Victoria whose bushland and forest are now extremely dry from lack of rain.[citation needed]
[edit] See also
[edit] References
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