2.4 Water in Australia
As we have already seen, it is not just the location of water that is important, but also the amount. Source 2.11 shows the four largest rivers in the world based on the volume of water that exits the river system as each enters its river mouth. Also included is the Murray–Darling – Australia’s largest and most important river system.
The 209 000 cubic metres of water that exits the Amazon River per second accounts for nearly onefifth of all the freshwater that drains into the oceans of the world, and yet the Amazon River basin is currently accessible to just 25 million people (0.4% of the world’s population). So much water pours out of the Amazon that the salt content and colour of the Atlantic Ocean are altered for a distance of about 320 kilometres from the mouth of the river.
Compare this to the Murray– Darling river system, where only 391 cubic metres of water exit per second. As we shall see in the next chapter, the Murray–Darling river basin is our most important farming region, producing around one-third of Australia’s food supply. Despite our reliance on this river system, the amount of water that travels through it is very small on a global scale. To put the volume of water the Amazon carries in perspective, the Murray–Darling’s length is more than the Amazon’s (3370 kilometres compared to the Amazon’s 6400 kilometres) and yet the Murray– Darling discharges less than 0.2% of the water that the Amazon discharges! So why such a difference? Let’s find out.
Investigate Lake Eyre and produce a digital presentation (e.g. PowerPoint, or a website using Weebly, Wix or Prezi), advertising it as a diverse and fascinating tourist destination. Present your advertisement as if you were the Lake Eyre representative at a tourism exhibition promoting Australia in another country. Include details on recent floods, cultural sites, the use of the land by Indigenous people, the changeable ecosystem (e.g. its role in the desert and as a periodic wetland environment) and any other interesting features of the region. You will find links to a number of useful websites at www.cambridge.edu.au/hass7weblinks.