Drought in Australia

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A dried up Lake Hume, 2007
Drought-affected fields in the Victorian countryside, 2006

Drought in Australia is defined by the Australian Bureau of Meteorology as rainfall over a three-month period being in the lowest decile of what has been recorded for that region in the past.[1] This definition takes into account that drought 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] Note that this definition uses rainfall only because long-term records are widely available across most of Australia. However, it does not take into account other variables that might be important for establishing surface water balance, such as evaporation and condensation.

Historical climatic records are now sufficiently reliable to profile climate variability taking into account expectations for regions.[3] Bureau of Meteorology records since the 1860s show that a ‘severe’ drought has occurred in Australia, on average, once every 18 years.[4] State Governments are responsible for declaring a region drought affected and the declaration will take into account factors other than rainfall.[1]

The worst drought to affect the country occurred in the 21st century–between the years 2003 to 2012. Nonetheless, many regions of Australia are still in significant drought and rainfall records have showed a marked decrease in precipitation levels since 1994, with many scientists attributing this to climate change and global warming.[5]

Droughts in the 19th century

  • 1803 Drought in NSW that produced severe crop failures.
  • 1809 Beginning of an unusually severe drought in NSW that continued until 1811.
  • 1813−15 Severe drought in NSW that prompted searches for new pastures.
  • 1826−29 Severe drought in NSW that caused Lake George to dry up and the Darling River to cease flowing.[6]

Since 1860, when adequate meteorological recording commenced, the most severe droughts have occurred commonly at intervals of 11 to 14 years. Major droughts that were recorded later in the 19th century include:

  • 1835 and 1838 Sydney and NSW receive 25% less rain than usual. Severe drought in Northam and York areas of Western Australia.
  • 1838−39 Droughts in South Australia and Western Australia
  • 1839 Severe drought in the west and north of Spencer Gulf, South Australia.
  • 1846 Severe drought converted the interior and far north of South Australia into an arid desert.
  • 1849 Sydney received about 27 inches less rain than normal.
  • 1850 Severe drought, with big losses of livestock across inland New South Wales (NSW) and around the western rivers region.
  • 1864−66 (and 1868). The little data available indicates that this drought period was rather severe in Victoria, South Australia, New South Wales, Queensland and Western Australia.
  • 1877 All States affected by severe drought, with disastrous losses in Queensland. In Western Australia many native trees died, swamps dried up and crops failed.
  • 1880 to 1886 Drought in Victoria (northern areas and Gippsland); New South Wales (mainly northern wheat belt, Northern Tablelands and south coast); Queensland (1881–86, in south-east with breaks – otherwise mainly in coastal areas, the central highlands and central interior in 1883–86); and South Australia (1884–86, mainly in agricultural areas).
  • 1888 Extremely dry in Victoria (northern areas and Gippsland); Tasmania (1887–89 in the south); New South Wales had the driest year since records began; Queensland (1888–89) had a very severe drought, with much native scrub dying and native animals perishing; South Australia had one of its most severe droughts; and Western Australia (central agricultural areas) lost many sheep.[8]
  • 1897 Drought in much of Queensland, compared to 1883-4 droughts.[9]

Drought in the 20th century

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A dried-up lagoon in Wagga Wagga, New South Wales during the 1912 drought.

During the severe, Australia wide, 1902 Federation Drought, the total sheep population dropped to fewer than 54,000,000 from a total of 106,000,000 sheep in 1891; and cattle numbers fell by more than 40 percent. It was 1925 before the sheep numbers reached the hundred-million mark again.

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 was dry at Bourke, New South Wales, for over a year, from April 1902 to May 1903. There was concern about Sydney's water supply.[10] In the 1911–1915 period, Australia suffered a major drought, which resulted in the failure of the 1914 wheat crop.[11]

During 1918 to 1920, a severe drought was experienced by Queensland, New South Wales, South Australia, Northern Territory (Darwin-Daly Waters area and central Australia), Western Australia (Fortescue area), Victoria, and Tasmania.

During World War II, eastern Australia suffered dry conditions which lasted from 1937 through to 1947 with little respite.[12] The end of the drought coincided with the 1946-47 Ashes series, it rained in all 25 matches played by the tourists, including two tropical rainstorms during the First Test at Brisbane and another in the Second Test at Sydney.[13] From 1965–68, eastern Australia was again greatly affected by drought. Conditions had been dry over the centre of the continent since 1957 but spread elsewhere during the summer of 1964/1965. This drought contributed to the 1967 Tasmanian fires in which 62 people died in one day and 1,400 homes were lost.[14] 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 over-all impact. There were severe dust storms in north-western Victoria and severe bushfires in south-east Australia in February 1983 with 75 people killed.[15] This El Niño-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[16] which intensified in 1994 and 1995 to become the worst on record in Queensland.[17] This drought was influenced by a strong El Niño weather pattern and associated with high temperatures in July and August 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".[18] So few wheat and barley crops survived, about half the usual for that year, that grains had to be imported from other states.[19]

In June 1994, more than ten towns had lost irrigation systems; and some areas had gone five years without decent rainfall.[18]

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.[20] 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.[20] The town of Warwick was particularly affected.

Drought in the 21st century

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Around 2000 Australia was prone to wet weather brought on by La Niña influenced weather patterns.

Green drought, caused by insufficient rain after a long dry period, November 2002

2002-2006

The section on 'Natural Disasters in Australia' found on the Australian Government website stated; "Eastern and Southern Australia is once again experiencing widespread drought, with agricultural income in 2006−07 expected to be at the lowest since 1994−1995".[21]

Then from 2003 a long, severe drought, again the worst on record[22] was experienced in many parts of Australia.

Rainfall deficiencies in 2006

As of 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 worsened by temperatures being the highest on record since the 1950s.[23][24]

Responses during 2006 and 2007

The drought 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.[citation needed] 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 voted on, and rejected, a referendum on using recycled sewerage water. However, after the referendum Toowoomba began using recycled sewerage water as no other feasible alternative was available.[citation needed] 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.[25] Likewise, the Victorian Government is also in the process of building one of the world's largest desalination plants. When complete, it will be capable of producing up to a third of Melbourne's water needs.[26]

Dairy producers have been hit particularly hard by the drought that has swept much of Australia. And 2004 was a particularly bleak year in the sector, as a drought-caused drop in production sent revenue in the industry down by 5.6%.[27]

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 and as of July 2009, water levels in its dams are at a mere 27% of capacity.[28]

Agricultural production has been affected. Australia's cotton production has dropped, 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.[29] 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.[30]

Stock feed is also becoming scarce and farmers are finding it difficult to feed cattle and sheep.[citation needed]

Predictions and observations for 2007−08

Dry paddocks in the Riverina region during the 2007 drought
Cattle on a sand island in the Murrumbidgee River which is normally underwater but due to low rainfall in the catchment during 2008 meant water releases from the dams were reduced.

In early 2007, senior weather forecasters predicted that the drought would ease along the east coast with a return to average rainfall from late February 2007. Forecasters believed that the El Niño effect that had been rampant during 2006 and 2007 had ended.[31] Heavy rainfall in June and July, particularly in coastal regions of New South Wales and in Victoria's Gippsland region, together with tentative forecasts of a La Niña event, brought hope that the drought may have ended.[32]

The Prime Minister at the time, John Howard, announced on 19 April 2007 that unless there was substantial rain in the next six weeks no water would be allocated to irrigators in the Murray-Darling basin for the coming year. The result of this would have directly affected the 50,000 farmers and the economy.[33] Electricity shortages may also have occurred if the Snowy Mountains Scheme had been forced to shut down its hydroelectric generators.[34]

However, in August 2007, the Darling River flowed again after nearly a year of no flows.[35] Inflows into the Murray-Darling Basin in the winter of 2007 were amongst the lowest on record though marginally better than those of the winter of 2006 which had been the driest on record.

The drought in Sydney eased around April 2008, when Sydney's main water catchments reached 65 percent, 25 per cent fuller than it was at the same time the previous year.[36] [37]

However Victoria remained drought affected, with Melbourne's water supplies dipping to around 30% by July 2008.[38]

In June 2008 it became known that an expert panel had warned of long term, maybe irreversible, severe ecological damage for the whole Murray-Darling basin if it did not receive sufficient water by October of that year.[39]

In Tasmania drought conditions worsened in 2008, with many areas reporting no significant rainfall for three years.[40]

Continuation into 2009–10

2009

Drought conditions in South East Australia continued, after one of the driest summers for the region. Melbourne had Stage 3a water restrictions from 1 April 2007, and narrowly avoided Stage 4 restrictions, with the minimum storage level of around 25.8% [41] remaining above the threshold of 25% for enacting Stage 4. This led to the construction of the North–South Pipeline which would divert water out of the Goulburn River and supply it to Melbourne to meet water demands. Many towns in Victoria were close to running out of water, with some of the few Victorian towns without water restrictions being in the East Gippsland water area, where reservoir levels were above 80%.

2010

Lua error in package.lua at line 80: module 'strict' not found. The 2010 Victorian storms in March did little to help Melbourne's storage levels, but steady winter rains, and the 2010 Victorian floods in September, caused storage levels to remain above about 32.7%,[42] rising to over 46% in September and 51% by late November.

2010 saw Australia officially record its wettest spring on record due to a moderate to strong La Nina which developed over the region. Water restrictions were reduced to stage 3 on 2 April, and stage 2 on 1 September.[43] 2010 also saw Melbourne reach average annual rainfall for the first time since 1996,[44] and its wettest spring since 1993.[45]

The drought in Queensland eased, Brisbane recorded very heavy rain in May 2009, and premier Anna Bligh announced that South East Queensland was no longer experiencing drought.[46] Brisbane's dams reached full capacity with the state in general experiencing its wettest spring on record. Widespread flooding occurred in eastern Australia throughout December and January.[47]

The drought in New South Wales also eased. In the beginning of 2010 the percentage of the state in drought was pushing 70%, and as of December 2010, the entire state was officially out of drought, with the entire state recording its wettest spring on record. Several rivers, including rivers in the outback had flooded several times, and many dams overflowed, including the Burrendong, Burrinjuck and Pindari Dams. Canberra's dams rose above 90%.

Despite Western Australia having experienced its fifth wettest spring on record, the South West, Gascoyne and Pilbara regions of Western Australia's drought intensified, with the region experiencing its driest year on records. Perth's dams registered its lowest inflows on record, with the city itself experiencing one of its driest years on record, along with the hottest spring on record.[48][49]

December 2010 was also the second wettest December on record for Australia.[47]

End declared in 2012

On 27 April 2012, Agriculture Minister Joe Ludwig stated that the two final areas in Australia receiving Federal "exceptional circumstances" drought support, Bundarra and Eurobodalla in New South Wales, would cease being eligible the following week.[50] The Federal Government had provided $4.5 billion in drought assistance since 2001.[51] The related move to end the exceptional circumstances interest rate subsidy program was criticised as premature by the NSW Farmers Federation and National Farmers' Federation.[50]

2013-2014

During 2013 serious rainfall deficiencies, heralding drought conditions, again began to develop and be sustained in mid-2013 through much of western Queensland.[52] Although these began easing for western Queensland in early 2014, drought began to develop further east, along the coastal fringe and into the ranges of southeast Queensland and northeast New South Wales.[53]


See also

References

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  8. Australian Encyclopaedia 1963, p. 288
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  24. Australian Drought and Climate Change, retrieved on 7 June 2007.
  25. Perth Seawater Desalination Plant
  26. http://www.ourwater.vic.gov.au/programs/desalination
  27. Dairy farmers face tough times
  28. http://www.conservewater.melbournewater.com.au/content/storage.asp
  29. 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
  30. Water and Cotton Fact Sheet of 13 February 2007 retrieved 5 March 2007 from Cotton Australia
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  38. Melbourne Water, water report
  39. BBC News: Australian rivers face disaster
  40. Lua error in package.lua at line 80: module 'strict' not found.
  41. Weekly Water Report, 19 June 2009
  42. Weekly Water report, 4 July 2010
  43. State government eases Melbourne's water restrictions, The Age
  44. Melbourne gets average rainfall for first time in 14 years, ABC Online
  45. Melbourne's wettest spring in 17 years, Weatherzone
  46. Drought over in SE Qld, ABC News, 20 May 2009
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  52. url=http://www.bom.gov.au/climate/drought/archive/20130805.shtml
  53. url=http://www.bom.gov.au/climate/drought/archive/20140807.shtml

External links