Study Notes
The water cycle is a continuous journey of water through Earth's systems, involving processes like evaporation, condensation, and precipitation. It is essential for recycling Earth's finite water supply and supports ecosystems and human activities.
- Evaporation — Liquid water transforms into water vapour from surfaces Example: Water evaporating from oceans and lakes
- Condensation — Water vapour transforms into liquid droplets, forming clouds Example: Cloud formation in the atmosphere
- Precipitation — Water falls to Earth as rain, snow, sleet, or hail Example: Rainfall replenishing rivers and lakes
- Infiltration — Water soaks into soil and porous rock layers Example: Rainwater entering the ground
- Transpiration — Plants release water vapour through leaf stomata Example: Moisture released by trees into the atmosphere
- Surface Run-off — Water flows over land into streams, rivers, and lakes Example: Rainwater flowing into a river
- Groundwater Flow — Water travels slowly through underground aquifers Example: Water moving through an aquifer to a well
- Interception — Vegetation catches water before it reaches the ground surface Example: Leaves catching raindrops
- Through-flow — Water moves laterally through soil towards rivers Example: Water moving through soil to a nearby stream
Exam Tips
Key Definitions to Remember
- Evaporation: Liquid to gas transformation
- Condensation: Gas to liquid transformation
- Precipitation: Water falling to Earth as rain, snow, sleet, or hail
- Infiltration: Water soaking into soil and rock
Common Confusions
- Evaporation only occurs at high temperatures
- Condensation is the same as precipitation
Typical Exam Questions
- What is evaporation? The process where liquid water transforms into water vapour.
- How does condensation occur? When water vapour cools and changes into liquid droplets, forming clouds.
- What role does the sun play in the water cycle? It provides energy for evaporation, driving the cycle.
What Examiners Usually Test
- Understanding of key processes like evaporation and condensation
- Ability to explain state changes in the water cycle
- Knowledge of how the water cycle supports ecosystems and human activities