Murray Darling Basin

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Map of the Murray Darling Basin

The Murray Darling Basin is Australia 's largest river system in a sedimentary basin and at the same time the largest fertile region in the southeast of the continent. The area is about 1,040,000 km².

However, it is also an area of ​​great cultural, historical and ecological value. The basin is named after the two most important rivers that drain it, the Murray River and the Darling River .

location

The Murray-Darling Basin spans south Queensland , most of New South Wales, and northern Victoria ; the estuary with Lake Alexandrina is in the state of South Australia . The basin is relatively uniform in terms of height distribution and varies between 0 and 100 m. Between the Great Artesian and the Murray Darling Basin there is a basement spur protruding from the plains and reaching heights of over 1000 m. This mountain spur is part of the old basement mountain complex, from which most of the Western Australian Tableland is built. The Murray-Darling Basin is bounded in the east and south-east by the Great Dividing Range , Australia's most important mountain range.

Fish fauna

About forty species of Australian fish live in the Murray Darling Basin. Among them are a dozen species endemic to these waters , such as the “ Murray Cod ” or the “ Silver Perch ”. The species have adapted to the special environmental conditions, such as irregular flooding and different drying times. However, more than half of these species are threatened. In 2001 a commission of experts estimated that the number of native fish has decreased by 90% compared to the time before European colonization. The decline is attributed to changes in flow conditions, thermal pollution, fish barriers, habitat destruction, changes in water quality and the onset of around a dozen alien fish species, including carp . There has been an increasing number of fish deaths recently . Much water is used for irrigation , for example for growing cotton and rice, which further exacerbates the consequences of droughts .

use

42% of Australia's agricultural land is in the Murray-Darling Basin. 40% of the country's food is produced in these areas. Due to climate change , however, the amount of water flowing through the basin is also declining, which could lead to crop failures and drought. The Intergovernmental Panel on Climate Change ( IPCC) found this in a report from 2007 on the Murray-Darling Basin, which speaks of a water decrease of ten to 25 percent.

Murray-Darling Basin Authority

A new national water law in 2007 saw the creation of the Murray-Darling Basin Authority (MDBA). The independent authority is to regulate the equitable use of the water in the Murray Darling Basin by the states of Queensland , New South Wales , Australian Capital Territory , Victoria and South Australia . The authority draws up plans that regulate the fair and sustainable use of water.

Residents on the lower reaches of the two rivers criticized the authority heavily in the late 2010s. The Murray-Darling Basin Authority , contrary to their own policy, over-watering the major Queensland agricultural companies that grow cotton and rice . The authorities have failed: the river has dried up on the lower reaches, the population is suffering from a lack of water and animals - cattle, wild animals and millions of fish - are perishing. An investigation commissioned by the South Australia government confirmed many of the allegations. However, the government and the MDBA rejected the criticism and justified the problems primarily with the major droughts.

Web links

Individual evidence

  1. ^ Fishes of the Murray - Darling Basin - An introductory guide , MDBA
  2. ^ Esther Blank: Australia: Drought in the largest river system. In: nzz.ch . March 10, 2019, accessed March 10, 2019 .
  3. ↑ http://www.dradio.de/dlf/sendung/forschak/1088641/
  4. ↑ Australia's Prime Minister prepares Farmer for a dusty disaster. In: Spiegel Online. April 20, 2007, accessed December 2, 2014 .
  5. ↑ About us. In: Murray-Darlin Basin Authority. October 9, 2015, accessed March 10, 2019 .
  6. ↑ Esther Blank: Australia fights over the last drops . In: Neue Zürcher Zeitung . March 9, 2019, p. 7 ( nzz.ch [accessed on March 10, 2019]).

Coordinates: 33 ° 30 ′ 0 ″  S , 145 ° 0 ′ 0 ″  E