Location And Characteristics
The Murray-Darling Basin is found in the eastern Highland ranging from Tambo in North Western Queensland to Seymour in southern Victoria, and from Goolwa in Southern Australia to Tenterfield in eastern NSW. It covers an area of over 1 million square kilometres. The Murray Darling Basin is a system comprising of over 20 major rivers, about 3 000 wetlands and 52 National Parks, the largest being Mt Kosciusko near Cooma, which is nearly 650 000 ha. The Basin comprises of one seventh of the surface area of Australia, with the Murray alone covering an area of 250 000 kilometres. The Murray Darling Basin comprises 26 major catchment areas in all, holding a gigalitre of water in each as recent.
Importance and Functions
The Murray Darling is most noted for being the largest catchment area in Australia. The landscape is home to a large number of plants and animals, many of which are unique to Australia. Originally 20 fish species, 24 frogs, 151 reptiles, 367 birds and 85 mammals were found within the basin. Many are now extinct or seriously threatened. The Basin is one of the most biologically rich areas in the world with the diversity of ecosystems ranging from temperate and semi-arid grasslands to open acacia and eucalypt woodlands and dense eucalypt forests. The Murray Darling Basin is extensively cleared for agriculture and it's not surprising that 40% of national produce is produced in it. As well as being used for agriculture, its 52 national parks, contribute to tourism and in return to Australia's economy. The Murray Darling Basin must be preserved as the variety of habitats it contains are essential for the surviving wildlife to prevent their extinction. Loss of habitat means loss of environment and in return loss of food for waterbirds, frogs and reptiles and their predators.
Nature of Environmental problem and causes
The Murray-Darling Basin has suffered two major pressures in recent causing declines on habitats and vegetation. These problems are salinity and water management. The causes of the problems and their effect should be assessed before attempts made to solve the problem are discussed. Both problems realte to water quality and quantity and therefore water management will be discussed first. More than seventy percent of the water in the Murray-Darling is being used for irrigation, grazing urban and industrial purposes. This means that there is not enough water to be shared between the Murray-Darling's to provide for it's 7 000 environments. Poor management of this water has resulted in the reduction of many wetlands by almost half, exacerbated salinity problems and encouraged the invasion of blue-green algae and exotic weeds. This problem is becoming more of a threat in recent years but is very difficult to fix as the water is needed elsewhere. Salinity is not, however only caused by water management. Salinity is also caused by the deforestation of trees to grow crops. When deep-rooted trees are cut...