Did You Know? Water Cycle

Subject: Geography | Year: 6

Name: _________________________ Class/Set: ____________ Date: ____________

• Ancient Refreshments: Believe it or not, the water you drank with your lunch today is the same water that existed when dinosaurs roamed the Earth. The Earth is a 'closed system', meaning it rarely gains or loses extra water; it simply recycles the same supply over and over through the water cycle.

• Frozen Time Capsules: While most water moves quickly through the cycle, some can stay 'trapped' for a very long time. In the coldest parts of Antarctica, some water has been frozen in glaciers for over 800,000 years without ever evaporating or melting!

• Botanical Breath: Plants play a massive role in the cycle through a process called 'transpiration'. A large oak tree can 'breathe' out (transpire) approximately 150,000 litres of water vapour every single year, which eventually rises to form clouds.

• The Salt Trap: Incredibly, although 70% of our planet is covered in water, only about 2.5% of it is fresh water that we can drink. Most of this is locked away in ice caps, leaving less than 1% of the world's water accessible for humans, plants, and animals to use.

• Solar Lifting: The sun is the powerful engine that drives the entire water cycle. Every day, the sun's heat evaporates over 1,000,000,000,000 (one trillion) tonnes of water from the Earth's surface, lifting it into the atmosphere as invisible vapour.

Quick Check Task

Examine: Read the facts above carefully and answer the following questions to consolidate your understanding.

Task A: Identify which specific process allows plants to contribute to the formation of clouds.

Task B: Explain why scientists describe the Earth as a 'closed system' in relation to its water supply.

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⚠ TEACHER’S GUIDANCE

Target Audience: Year 6 (Key Stage 2) Focus: Enhancing Tier 2 vocabulary (transpiration, accessible, closed system) and correcting the misconception that new water is 'created'.

Pedagogical Opportunities:

• Discussion Point: Ask students to consider the ethical implications of Fact 4 (The Salt Trap). If only 1% of water is accessible, how should we manage our water usage?
• Misconception Alert: Ensure students understand that 'evaporation' is not just from the sea, but from any moist surface, including puddles, soil, and even human skin.
• Oracy Strategy: Use a 'Think-Pair-Share' for Fact 1. Ask: "If we are drinking dinosaur water, does that mean the water cycle is the world's oldest recycling project?"

Answer Key & Mirror-Labeling:

• Task A Answer: The process is transpiration, where plants release water vapour into the atmosphere.
• Task B Answer: Earth is a closed system because it does not exchange matter with its surroundings; the total amount of water remains constant, it simply changes state (solid, liquid, gas) and location.