Year 7 Geography lesson plans

- Explain the processes of the water cycle. - Describe how Earth's water is distributed. - Explain why water is a scarce resource in Australia and how it is managed. Success criteria: - I can describe evaporation, condensation, precipitation and runoff. - I can explain why only a small fraction of Earth's water is easily usable. - I can describe two ways water is managed in Australia.

- A clear bowl, plastic wrap, a small cup, ice cubes and warm water (water cycle model) - A map of Australia's rainfall - Notebook

Introduce today's words: - water cycle: The continuous movement of water between the oceans, atmosphere and land. - evaporation: When liquid water is heated and turns into water vapour. - precipitation: Water falling from clouds as rain, hail, sleet or snow. - groundwater: Water stored underground in soil and rock layers called aquifers. - catchment: An area of land where rainfall drains into a river, lake or dam. - renewable resource: A resource that can be replaced naturally over time. Ask your child what they already know about water as a resource.

Water moves constantly in the water cycle. The sun heats water in oceans, lakes and rivers, causing evaporation. Plants also release water vapour (transpiration). As vapour rises and cools, it condenses into clouds (condensation). When droplets become heavy, they fall as precipitation. Water then flows over land as runoff into rivers and oceans, or soaks into the ground to become groundwater. About 97% of Earth's water is salt water in the oceans. Only about 3% is fresh water, and most of that is frozen in ice caps and glaciers or stored deep underground. Less than 1% of all water is easily accessible fresh water in lakes, rivers and shallow groundwater. Water is a renewable resource because the water cycle replaces it, but it can still run short when people use it faster than it is replaced or when it is polluted. Australia is the driest inhabited continent. Rainfall is highly variable from year to year, droughts are common, and much of the inland receives little rain. Most people live near the coast, where rainfall is higher. Water is managed by building dams, protecting catchments, recycling wastewater, desalination plants (which remove salt from seawater, used in several capital cities), water restrictions and pricing. The Murray–Darling Basin, covering about one-seventh of Australia, is managed under a basin-wide plan that shares water between farms, towns and the environment. Water has deep cultural and spiritual significance for First Nations peoples. Knowledge of waterholes, soaks and seasonal flows has been maintained for thousands of years, and many Traditional Owners are seeking a greater say in how water is managed.

Modelling the water cycle Explain what happens in a bowl of warm water covered with plastic wrap with ice on top. Step 1: Warm water evaporates into vapour (evaporation). Step 2: Vapour touches the cold plastic and turns into droplets (condensation). Step 3: Droplets grow and fall back down (precipitation). Answer: The model shows evaporation, condensation and precipitation. Calculating available water If a model 'Earth' had 1,000 litres of water and 97% were salt water, how many litres would be fresh? Step 1: Fresh = 100% − 97% = 3%. Step 2: 3% of 1,000 L = 0.03 × 1,000 = 30 L. Answer: 30 litres would be fresh, and most of that would be frozen or underground.

1. What is condensation? (a) Water vapour cooling to form droplets (b) Water falling as rain (c) Water soaking into the ground (d) Ice melting 2. Approximately what percentage of Earth's water is salt water? (a) 50% (b) 75% (c) 97% (d) 3% 3. Where is most of Earth's fresh water stored? (a) In rivers (b) In lakes (c) In clouds (d) In ice caps and glaciers 4. What does a desalination plant do? (a) Turns fresh water into salt water (b) Removes salt from seawater (c) Makes clouds (d) Builds dams

5. Why is water management a challenge in Australia? (a) Rainfall is low in many areas and highly variable (b) It rains equally everywhere (c) There are no rivers (d) Nobody uses water 6. Water stored underground in aquifers is called ____. 7. Rain, hail, sleet and snow are all forms of ____. 8. An area of land where rainfall drains into a river or dam is a ____.

- Can you describe evaporation, condensation, precipitation and runoff? - Can you explain why only a small fraction of Earth's water is easily usable? - Can you describe two ways water is managed in Australia? - What was the trickiest part today?

1. Water vapour cooling to form droplets — Condensation turns vapour into liquid droplets, forming clouds. 2. 97% — About 97% of Earth's water is in the oceans. 3. In ice caps and glaciers — Most fresh water is frozen in ice caps and glaciers. 4. Removes salt from seawater — Desalination removes salt to produce drinking water. 5. Rainfall is low in many areas and highly variable — Australia's rainfall is low and unreliable in many regions. 6. groundwater — Groundwater fills spaces in soil and rock. 7. precipitation — Precipitation is water falling from clouds. 8. catchment — Catchments collect and channel rainfall.

Recap the success criteria together. Watch for these common misconceptions: - Many think renewable means unlimited. Water can be overused or polluted faster than it is replenished. - Some think the water cycle is a neat circle. Water can be stored for very long periods in ice, deep groundwater or oceans.

- Build and photograph a water cycle model, labelling each process. - Conduct a household water audit for one week and suggest three savings. - Research how one capital city secures its water supply.

- Revisit water as a resource tomorrow with two or three quick questions from memory. - Try the online practice check for this topic and look at any questions that need another go.

- Read your household water bill together and calculate daily water use per person. - Visit a local dam, wetland or water treatment education centre. - First Nations cultural knowledge of water can be sacred or restricted. Learn from material that communities and organisations have chosen to share publicly, and from local First Nations organisations.