Year 7 Science · Unit 2 · Lesson 12
Apply Worksheet
Learning Goals
Order the steps
Number the events from 1 to 8 to show the correct order of a water molecule's journey. Event 1 = what happens first.
| Order | Event |
|---|---|
| Water vapour cools as it rises over the Great Dividing Range, forming clouds by condensation. | |
| Runoff from the Darling Downs flows into the Darling River, joining the Murray–Darling system. | |
| Water falls as precipitation (rain) over the mountains of the Great Dividing Range. | |
| Solar energy causes evaporation from the surface of the Southern Ocean. | |
| The Murray River carries the water south-west toward the Southern Ocean at Encounter Bay, SA. | |
| Water vapour rises off the ocean and is carried inland by prevailing winds. | |
| The water evaporates again from the ocean, completing the cycle. | |
| Runoff from the mountains flows into rivers, feeding the Murray-Darling Basin. |
Real-world context
The Murray-Darling Basin covers approximately 1 million km² across Queensland, NSW, Victoria and South Australia. It provides water for 3.2 million people and 40% of Australia's agricultural production, including cotton, rice, almonds and fruit. However, the Murray River sometimes fails to reach the sea at Encounter Bay. The Millennium Drought (2001–2009) severely reduced river flows, and the Murray-Darling Basin Plan (introduced 2012) attempts to return some water to the environment by reducing irrigation licences.
(a) Which water cycle processes bring water into the Murray-Darling Basin? Name at least three and explain what each contributes.
(b) How does large-scale irrigation farming disrupt the natural water cycle in the Basin? What happens to the water that is diverted for crops?
(c) If the Murray River fails to reach the sea, why does this matter for river ecology and for communities in South Australia who rely on the river?
Wrap Up
In one sentence, what was the main idea of this lesson?