Excerpt
CONTENTS
LIST OF FIGURES
1 Scope and aim of the paper
2 Australia’s climate situation
3 The Murry Darling Basin
4 Measures taken for mitigation of water shortage
5 The Murray Darling Basin from an integrated perspective
6 Weaknesses of current water management
7 Conclusion
REFERENCES
LIST OF FIGURES
Figure 1: Trend in mean annual rainfall
Figure 2: Location of the Murray Darling Basin
Figure 3: Map of land use across Australia and major agricultural zones
1 Scope and aim of the paper
The Murray Darling Basin, located in the south eastern part of Australia, is the countries largest catchement area and main water reservoire for the cities and the agriculture. Historically and now even more in the course of climate change, Australia is facing significant water shortages. The Murray Darling Basin is running out of water and thus challenging the habits of Australians in the cities and in rural agriculture. The tense situation is a challenge in environmental, socio-economic and cultural regards. Understanding the problematical situation and its historical development over time as well as developing measures to be taken in order to improve conditions in a sustainable way is demanding a wide scope and persepective. Revealing and describing the different factors and the complex interdependencies requires an integrative approach.
The aim of this paper is to describe the specific situation of the Murray Darling Basin and to put it into an integrative context. This integrative context will deliberately embrace several concepts to show the multiplicity of the situation. In this specific case I examine the concept of human ecology for a wide understanding of the problem of water shortage itself. In the further discussion about current problems and challenges of water resource management I will take a closer look at the concept of environmental justice. Based on that, I will figure out the weaknesses of current measures taken by the stakeholders in Australia.
2 Australia’s climate situation
Australia is a large continent spanning tropical, sub-tropical and temperate climatic zones. Temperature trends in Australia over the past century are consistent with global trends in showing a more or less steady warming. Australia is the driest inhabited continent on earth and its water resource issues are intimately related to prevailing rainfall distribution. The availability of water is thus more critical than a rise in temperature per se and crucial to maintain the pattern of habitation and agriculture (Steffen et al., 2010; Risbey, 2010).
The northwestern part of the country has become wetter while a pronounced drying trend has appeared in the south west and along the east coast, the region where most of the Australian population lives and where much of the agricultural activity occurs (see Figure 1, Steffen et al., 2010). Furthermore eastern Australia is subject to effects of the El NiñoSouthern Oscillation phenomenon, experiencing major droughts during these periods (Steffen et al, 2010).
An additional concern is that the southern coast and cities (Perth, Adelaide, Melbourne, Hobart, Sydney) are dependent on the passage of frontal systems to provide much of their rainfall. If these systems were to contract to the south as a result of greenhouse or ozone forcing of the climate (Hartmann et al. 2003; Karoly 2003), there is potential for major rainfall reductions in these regions.
illustration not visible in this excerpt
Figure 1: Trend in mean annual rainfall
Though rainfall is hard to project in models, one of the consistent results that emerges is that the dry regions tend to get dryer and wet regions wetter under greenhouse scenarios (Hansen et al. 1998; Houghton et al., 2001). With the second highest rate of CO2 emissions per capita and 4.5 times the global average Australia is further contributing to climate change and thus boosting the risk of growing water shortage (Preston and Jones, 2006). Consequently the water supply situation is likely to worsen in the future and resources may be the ‘Achilles heel’ of Australia under climate change (Risbey, 2010).
3 The Murry Darling Basin
The Murray Darling Basin is by far the most significant agricultural area in Australia. The name is derived from the two largest rivers Murray River and Darling River. The largest part of the basin is located in the state of New South Wales, spanning into Queensland, Victoria, South Australia and the considerably small Autralian Capital Territory (see Figure 2).
illustration not visible in this excerpt
Figure 2: Location of the Murray Darling Basin
The basin is the largest catchment area of Australia and the main source of water supply for most of the country’s major cities and the lion’s share of the nation’s agriculture.
Agricultural production follows the rainfall regions and the major river valleys that spring from these regions. Major agriculture thus favours the east and south coasts and inland regions such as the Murray Darling basin (Risbey, 2010).
Irrigation in Australia is a widespread practice to supplement low rainfall levels in Australia with water from other sources. Most of Australias cropping and irrigated agriculture is located in and around the Murray Darling Basin (see Figure 3).
illustration not visible in this excerpt
Figure
3: Map of land use across Australia and major agricultural zones
Characterised by its vast flatness, rain falls into large storages located along the eastern mountainous border, and drains south west through multiple interconnecting networks of natural water courses and into man- made irrigation canals. The Murray Darling Basin accounts for roughly 34 per cent of Australia’s agricultural production by gross national value and 75 per cent of its irrigated area. Of the approximately 13,000 gigalitres of flow in the basin, which studies have shown to be divertible, 11,500 gigalitres per annum is removed for irrigation, industrial use, and domestic supply (Bentley, 2007).
Agriculture is a major backbone of the Austrailan economy.and droughts cause significant effect on GDP. The 2002-2003 drought for example resulted in an estimated drop of 1,6 per cent in GDP loss of 70.000 jobs (Steffen et al., 2006).
Besides irrigated agriculture the major cities like Sydney, Melbourne, Brisbane and Adelaide do receive a large amount of their drinking water. The latter for example gets a normal annual rainfall of 545.3 mm (BoM, 2009). For comparison the German city of Munich receives approximately 849 mm per year for a comparable amount of population. In a drought year Adelaide sources up to 90 per cent of its water from the River Murray (Department of Climate Change, 2009). All major cities have instituted major water restrictions, with Melbourne and Adelaide declaring some of them permanent (Risbey, 2010).
The decrease in rainfall over the last decades, the massive overexploitation of water for agriculture and urban use plus effects of climate change resulted in sinking water levels with partial drying out of the rivers and thus significant water shortages. Inflows into the basin are currently the lowest on record and and river flows in the basin are expected to decrease by 16 to 48 per cent for a 3-4ºC warming (Bentley, 2007; Beare and Heaney, 2002). If flows in Murray Darling river system halve, the agricultural mix is considered not be sustainable. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has forecasted that climate change will cause decreased precipitation over much of Australia and that this will exacerbate existing challenges to water availability and quality for agriculture (Preston and Jones, 2006).
Overuse and poor irrigation practices have furthermore led to increased salt content in the soil, reducing the productivity of the soil.
[...]