Drought in Australia

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Drought in Australia defined 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]

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]

Drought-affected fields in the Victorian countryside

[edit] Droughts in the 19th century

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 in the 19th century include:

1829 Major drought in Western Australia with very little water available.

1835 and 1838 Sydney and NSW receive 25% less rain than usual. Severe drought in Northam and York areas of 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 l868). 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.^[4]

[edit] Drought in the 20th century

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 per cent. 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.^[5] In the 1911-1915 period, Australia suffered a major drought which resulted in the failure of the 1914 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. 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.^[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 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 few wheat and barley crops survived, 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 21st century

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

Green drought, caused by insufficient rain, Nov 2002

Then from 2003 a long, severe drought, again the worst on record^[15] was experienced in many parts of Australia.

[edit] 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.^[16][17]

[edit] Responses during 2006 and 2007

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.^{[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.^[18]

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 4.5%^[19].

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 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.^[20] 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.^[21]

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

[edit] Predictions and observations for 2007-2008

Dry paddocks in the Riverina region during the 2007 drought

Cattle on an sand island in the Murrumbidgee River which is normally underwater but due to low rainfall in the catchment during 2008 has meant water releases from the dams have been 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.^[22] 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.^[23]

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 will be allocated to irrigators in the Murray-Darling basin for the coming year. The result of this would directly affect the 50,000 farmers and the economy and the price of food would significantly rise, contributing to inflation.^[24] Electricity shortages are also likely if the Snowy Mountains Scheme is forced to shut down its hydroelectric generators.^[25]

In August 2007, the Darling River flowed again after nearly a year of no flows.^[26] 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.

As of April 2008, NSW was moving out of drought. Sydney's main water catchments are at 65.4 percent, 25 per cent fuller than it was at this time last year. Sydney Water stated with no more rain and unchanged demand, Sydney now has enough water in storage to last for 3.1 years. ^{[27] [28]}

Central Victoria remains drought affected. At the end of April 2008, Melbourne's water storages are at a combined 31.5%.^[29]

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 does not receive sufficient water by October^[30].

[edit] Drought and population levels in Australia

Some members of the Australian environmental movement, notably the organisation Sustainable Population Australia, believe that as the driest inhabited continent, Australia cannot continue to sustain its current rate of population growth without becoming overpopulated. SPA also argues that climate change will lead to a deterioration of natural ecosystems through increased temperatures, extreme weather events and less rainfall in the southern part of the continent, thus reducing its capacity to sustain a large population even further.^[31] In response to this, there are several movements and campaigns around the country which are advocating for environmental action. One such campaign is "The Big Switch", claimed as Australia's largest community climate change campaign. ^[32]

The UK-based Optimum Population Trust supports the view that Australia is overpopulated, and believes that to maintain the current standard of living in Australia, the optimum population is 10 million (rather than the present 20.86 million), or 21 million with a reduced standard of living.^[33]

[edit] See also

• Climate change in Australia
• Deserts of Australia
• Extreme weather
• Federation Drought
• List of reservoirs and dams in Australia
• Water restrictions in Australia

[edit] References

[edit] External links

• Drought
• Drought in Australia
• Drought in Australia
• Drought in Australia a natural phenomenon