Hi there, young learners! Welcome back to Primary 4 Basic Science & Technology. In our previous lesson, we learned about water (ice) – freezing. Today, we’re going to learn about the Water Cycle.
Objectives
By the end of this lesson, you should be able to:
- Define the water cycle and identify its main elements.
- Explain why streams and rivers dry up.
- Illustrate the water cycle on paper.
Water Cycle
The water cycle is a continuous process where water moves around, above, and below the Earth’s surface. It’s like a big, never-ending journey for water!
What is the Water Cycle?
The water cycle is a natural process that describes how water changes its state (solid, liquid, gas) and moves through different parts of the Earth. It’s a continuous cycle, meaning it never stops!
Elements of the Water Cycle
Some of the main elements of the water cycle include:
- Evaporation: When the sun heats up water in rivers, lakes, and oceans, it turns into vapor and rises into the air.
- Condensation: As the water vapor rises, it cools down and turns back into tiny water droplets, forming clouds.
- Precipitation: When the water droplets in clouds become too heavy, they fall back to Earth as rain, snow, sleet, or hail.
- Collection: The water that falls back to Earth collects in rivers, lakes, oceans, and underground. This water then evaporates again, starting the cycle all over.
Drying Up of Streams
Streams and rivers can dry up during certain seasons, especially in dry areas. This happens because:
- Less Rainfall: During dry seasons, there is less rain, so there is less water flowing into streams and rivers.
- Increased Evaporation: The sun’s heat causes more water to evaporate from streams and rivers, leaving less water behind.
The water that evaporates from streams and rivers doesn’t disappear. It rises into the air and becomes part of the water cycle. It will eventually fall back to Earth as rain during the rainy season.
Evaluation Questions
Now that you’ve learned about the water cycle, let’s see if you can answer these questions:
- What is the water cycle?
- Name three elements of the water cycle.
- Why do streams and rivers dry up during certain seasons?
- How does the water cycle affect our daily lives?
- Can you draw a simple diagram of the water cycle?
Conclusions or Summary
Today, we learned about the water cycle, which is a continuous process that moves water around the Earth. We learned about the different elements of the water cycle, including evaporation, condensation, precipitation, and collection. We also learned why streams and rivers dry up during certain seasons.
Don’t forget to check the comments section if you have any questions, and use the navigation to move to the next lesson. See you in the next lesson!
