General MDB

Importance of water as a resource

• Water is unevenly distributed

• There is a high variability in annual amount of rainfall. Australia's rainfall in 2009

was 453mm, which was slightly below the long-term average (1961-1990) of

464mm (BOM 2010b).

• There are high levels of evaporation

• Australia is the driest inhabited continent: 80% arid or semi-arid

• Australia has the second highest per capita consumption of water in the world.

Irrigation is Australia’s major water use

• Australia experienced a 12 year (1998-2010) drought which has been followed by

two years of above average rainfall.

Water Use in Australia

Source: State of the Australian Environment 2006

Irrigated areas of Australia 1997

What are the Geographic characteristics of the Murray-

Darling Basin region ? “What is there? What is it like?”

• Characteristics might include: location, size, shape

• Natural Features: Slope, soil types, wildlife, vegetation, climate, river Systems

• Human Features: land uses (agriculture, urban), roads, buildings, infrastructure (dams, irrigation channels)

• Not all regions of the Basin are the same and water availability and water use vary between regions. Summarise the geographic characteristics of various sub-regions of the MDB.

• Know the location of some of the major features of the Basin (towns, rivers, wetlands, agricultural regions) See 2011 Exam Question 1

About the MDB

• Area: The basin covers 1 061 469 km2, equivalent to 14% of Australia’s landmass or the size of South Africa.

• It is one of the world’s major river systems.

• It has 6% of Australia’s run-off but more than half the country’s water use occurs here.

Many rivers contributeMajor tributaries of the Murray Darling.

Source: http://www.anao.gov.au/Publications/Audit-Reports/2010-2011/Restoring-the-Balance-in-the-Murray-Darling-Basin/Audit-brochure

Rainfall varies with seasons

Annual Rainfall in the MDB is unevenlydistributed

Annual Rainfall Murray Darling Basin is uneven

Source: Bureau of Meteorology 2010 Annual Rainfall - Murray Darling Basin

Annual rainfall is uneven - anomaly's

Distribution of climatic regions

The contribution of water to theMurray-Darling system is uneven

Source: NP page 40

Ground water supplements rainfall

Fractured rockSedimentarySurficial

Flows in MDB rivers are naturally variable

The Darling dried up 48 times at Menindee, between 1885 and 1960

• Floods Balonne - Jan 2011

The Murray Darling Basin rivers are floodplain Riversrivers

2 Million people live in the MDB

Albury Wodonga

Canbera

Mildura

Water use varies

Corryong – Headwaters of the Murray river

Rice Growing: Griffith NSW

Grape-growing: Griffith NSW

Confluence of Darling and Murray Rivers, WentworthNSW

Murray Gorge - SA

The Coorong and Murray Mouth South Australia

Example questions and answers

• Describe the Geographic Characteristics of theMDB?

Not such a good answer• It’s big• The rivers are long• Farmers grow crops there• Some towns get their water from the river• A lot of people live there.• People have built dams and changed the river.• There are some problems with the water in the• river.• The rivers flow through a few states• Lots of people go there on their holidays

Good answer• The MDB covers 1 million square kilometres, equivalent to the size of France and Spain(It• extends over75% of NSW, 60% of Victoria ,14% of Qld ,7% of SA,100% of ACT)• The Murray is 2375 kms long and the Darling is 1472 km long• It is a regulated river and in an average year 35% of the total water flow is diverted.• It is naturally salty, but some human activities have increased the amount of salt in the• river.• In other parts of the world the amount of the water in a river increases as the river• approaches the mouth. In the Murray the opposite is the case.• Approx. 2 million people live in the Basin area and many cities and towns rely on the river• for drinking water (including Adelaide)• The MDB produces 40% of the total gross value of Australia’s agricultural product,• including 70% of irrigation production.• Mining and mineral production - $1.66 billion per year• Manufacturing - in excess of $13 billion per year• Forestry - more than $1.2 billion in wood and paper products• Electricity generation - Basin has over 75% of the mainland’s hydro electric power stations• In total, tourism in the MDB is worth over $3444.5 million.