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.^[1] 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. Specifically drought in Australia is defined in relation to a rainfall deficiency of pastoral leases and is determined by decile analysis applied to a certain area ^[2]

Historical climatic records are now sufficiently reliable to profile climate variability taking into account expectations for regions.^[3] State Governments are responsible for declaring a region drought affected and the declaration will take into account factors other than rainfall.^[1]

Contents 1 General Characteristics 2 Drought in the twentieth century 3 Drought in the twenty first century 3.1 Rainfall deficiencies in 2006 3.2 Responses to the 2006 drought 4 See also 5 External Links 6 References

[edit] General Characteristics

Much of Australia receives typically low rainfall. The resulting dryness of the Australian continent is comparatively very high.

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. Water supply networks can be affected as can power stations that require a supply of fresh water.

Authorities and individuals are forced to find new sources of water and implement rationing schemes of dwindling water supplies when precipitation fails to fill reservoirs. The Australian federal Government provides drought assistance in exceptional circumstances through the Department of Agriculture, Fisheries and Forestry.^[4]

Rainwater harvesting efforts gain favour, water pressure reductions occur and outdoor water-use restrictions are typically applied. In recent years large cities like Toowoomba and Brisbane have had water restrictions implemented to save water as drought has reduced the inflow to dams which were built for water supply.

[edit] Drought in the twentieth century

At the time of Federation, Australia suffered a major drought. There had 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.^[5] In the 1914-1918 period, Australia suffered a major drought which resulted in the failure of the 1915 wheat crop.^[6]

During World War II, eastern Australia suffered dry conditions which lasted from 1937 through to 1947 with little respite.^[7] 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.^[8] 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.^[9] This El-Nino related drought ended in March when a monsoon depression became an extratropical low and swept across Australia's interior and on to the south-east in mid to late March.

A very severe drought occurred in the second half of 1991 ^[10] which intensified in 1994 and 1995 to become the worst on record in Queensland. ^[11] This drought was influenced by a strong El Nino weather pattern and associated with high temperatures in July and August of 1995, the fifth continuous year of drought in parts of Queensland. According to Primary Industries Minister, Ed Casey, "the drought affected region stretched in a 200 km to 300 km wide strip from Stanthorpe to Charters Towers". ^[12] So many wheat and barley crops failed, about half the usual for that year, that grains had to be imported from other states. ^[13].

In June 1994, more than 10 towns had lost irrigation systems and some areas had gone five years without decent rainfall^[12].

A part of the upper Darling River system collapsed during this drought. By October 1994, the Condamine River was exhausted, reverting to a series of ponds. Across the state more than 13 000 properties, totaling 40% of Queensland was drought declared^[14] The flow past Goondiwindi was the lowest since 1940. Cotton farms near Moree and Narrabri had been allocated no water for irrigation which resulted in a major loss of production^[14]. The town of Warwick was particularly affected.

[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^[15] was experienced in many parts of Australia. In 2006 it was declared a 1000-year drought event^[16].

[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.^[17]

[edit] Responses to the 2006 drought

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 have 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 completed a seawater desalination plant that will supply the city with 17% of its needs.^[18]

Most Australian mainland capital cities are facing a 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 tighter water restrictions.

Agricultural production has been affected. Australia's cotton production has fallen with the smallest area planted in 20 years, a 66% reduction compared to five years ago (considered a ‘normal’ year). The crop has been half its usual size for three of the past five years. Water use by the industry fell by 37% between 2000/01 and 2004/05, due mainly to drought.^[19] In the order of 20 cotton communities and 10,000 people directly employed by the cotton industry are impacted by the drought. The main areas affected are in New South Wales: Menindee where the area under production has reduced by 100%, Bourke has reduced the area under production by 99%, Walgett has reduced the area under production by 95%, the Macquarie River has reduced the area under production by 74% and the Gwydir River has reduced the area under production by 60%. In Queensland the worse affected areas are Biloela which has reduced the area under production by 100%, at Dirranbandi there has been a 91% reduction, Central Highlands has reduced the area under production by 82% and Darling Downs has reduced the area under production by 78%. Bourke has only had adequate water for one cotton crop in the last five years.^[20]

[edit] See also

• Deserts of Australia
• Extreme Weather
• List of reservoirs and dams in Australia
• Water restrictions in Australia

[edit] External Links

• Drought in Australia - Feature from Daily Telegraph

[edit] References

1. ^ ^{a b} Drought. Climate Glossary. Bureau of Meteorology (2006). Retrieved on 2006-11-13.
2. ^ Tapper, Nigel. & Hurry, Lynn. (1993) Australia's Weather Patterns: An Introductory Guide. Pages 51 -57. Dellasta. ISBN 1-875627-14-6
3. ^ Our Natural Resources at a Glance - Climate. Department of Agriculture, Fisheries and Forestry (Australia) (2006). Retrieved on 2006-11-13.
4. ^ Drought and Exceptional Circumstances. Climate Impact Sciences Program. Department of Agriculture, Fisheries and Forestry (Australia) (2006). Retrieved on 2006-11-13.
5. ^ The "Federation Drought", 1895-1902. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.
6. ^ The 1914-15 drought. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.
7. ^ The World War II droughts 1937-45. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.
8. ^ The 1965-68 drought. Climate Education. Bureau of Meteorology (1999). Retrieved on 2006-11-13.
9. ^ Short but sharp - The 1982-83 droughts. Climate Education. Bureau of Meteorology. Retrieved on 2006-11-13.
10. ^ Rankin, Robert. (1992) Secrets of the Scenic Rim. Rankin Publishers ISBN 0-9592418-3-3 (page 151)
11. ^ Collie, Gordon. Worst drought of century cripples farmers. The Courier Mail p. 14 26 August 1995
12. ^ ^{a b} Collie, Gordon. Water crisis threatens towns. The Courier Mail p. 3 3 June, 1995
13. ^ Coleman, Matthew. Crops worth $50m lost. The Courier Mail. 30 August 1995
14. ^ ^{a b} Collie, Gordon. Dry tears of despair. The Courier Mail. p. 29 22 October 1994.
15. ^ "Rural News 03/09/2003: Worst drought on record", ABC, 2003-09-03. Retrieved on 2006-11-17.
16. ^ This drought continues to this day and the Australian government is considering several alternative water supplies, including treating sewage, and desalination"Australia's dry horrors 'worst for 1000 years'", The New Zealand Herald, 2006-11-08. Retrieved on 2006-11-17.
17. ^ "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.
18. ^ http://www.watercorporation.com.au/D/desalination.cfm
19. ^ ABS Water Account Australia 2004/05 figures quoted by Water and Cotton Fact Sheet of 13 February 2007 retrieved 5 March 2007 from Cotton Australia
20. ^ Water and Cotton Fact Sheet of 13 February 2007 retrieved 5 March 2007 from Cotton Australia